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Fabrizio Ferro

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DOI: 10.1209/0295-5075/96/21002
2011
Cited 240 times
First measurement of the total proton-proton cross-section at the LHC energy of \chem{\sqrt{s} = 7\,TeV}
TOTEM has measured the differential cross-section for elastic proton-proton scattering at the LHC energy of analysing data from a short run with dedicated large-β* optics. A single exponential fit with a slope B=(20.1±0.2stat±0.3syst) GeV−2 describes the range of the four-momentum transfer squared |t| from 0.02 to 0.33 GeV2. After the extrapolation to |t|=0, a total elastic scattering cross-section of (24.8±0.2stat±1.2syst) mb was obtained. Applying the optical theorem and using the luminosity measurement from CMS, a total proton-proton cross-section of (98.3±0.2stat±2.8syst) mb was deduced which is in good agreement with the expectation from the overall fit of previously measured data over a large range of center-of-mass energies. From the total and elastic pp cross-section measurements, an inelastic pp cross-section of was inferred.
DOI: 10.1209/0295-5075/101/21002
2013
Cited 223 times
Measurement of proton-proton elastic scattering and total cross-section at \chem{\sqrt {s} = 7\,TeV}
At the LHC energy of , under various beam and background conditions, luminosities, and Roman Pot positions, TOTEM has measured the differential cross-section for proton-proton elastic scattering as a function of the four-momentum transfer squared t. The results of the different analyses are in excellent agreement demonstrating no sizeable dependence on the beam conditions. Due to the very close approach of the Roman Pot detectors to the beam center (≈5σbeam) in a dedicated run with β* = 90 m, |t|-values down to 5·10−3 GeV2 were reached. The exponential slope of the differential elastic cross-section in this newly explored |t|-region remained unchanged and thus an exponential fit with only one constant B = (19.9 ± 0.3) GeV−2 over the large |t|-range from 0.005 to 0.2 GeV2 describes the differential distribution well. The high precision of the measurement and the large fit range lead to an error on the slope parameter B which is remarkably small compared to previous experiments. It allows a precise extrapolation over the non-visible cross-section (only 9%) to t = 0. With the luminosity from CMS, the elastic cross-section was determined to be (25.4 ± 1.1) mb, and using in addition the optical theorem, the total pp cross-section was derived to be (98.6 ± 2.2) mb. For model comparisons the t-distributions are tabulated including the large |t|-range of the previous measurement (TOTEM Collaboration (Antchev G. et al), EPL, 95 (2011) 41001).
DOI: 10.1103/physrevlett.111.012001
2013
Cited 200 times
Luminosity-Independent Measurement of the Proton-Proton Total Cross Section at<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>8</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>TeV</mml:mi></mml:math>
The TOTEM collaboration has measured the proton-proton total cross section at √s=8 TeV using a luminosity-independent method. In LHC fills with dedicated beam optics, the Roman pots have been inserted very close to the beam allowing the detection of ~90% of the nuclear elastic scattering events. Simultaneously the inelastic scattering rate has been measured by the T1 and T2 telescopes. By applying the optical theorem, the total proton-proton cross section of (101.7±2.9) mb has been determined, well in agreement with the extrapolation from lower energies. This method also allows one to derive the luminosity-independent elastic and inelastic cross sections: σ(el)=(27.1±1.4) mb; σ(inel)=(74.7±1.7) mb.
DOI: 10.1016/j.nuclphysb.2015.08.010
2015
Cited 154 times
Evidence for non-exponential elastic proton–proton differential cross-section at low |t| and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>8</mml:mn><mml:mspace width="0.25em" /><mml:mtext>TeV</mml:mtext></mml:math> by TOTEM
The TOTEM experiment has made a precise measurement of the elastic proton–proton differential cross-section at the centre-of-mass energy s=8TeV based on a high-statistics data sample obtained with the β⁎=90m optics. Both the statistical and systematic uncertainties remain below 1%, except for the t-independent contribution from the overall normalisation. This unprecedented precision allows to exclude a purely exponential differential cross-section in the range of four-momentum transfer squared 0.027<|t|<0.2GeV2 with a significance greater than 7σ. Two extended parametrisations, with quadratic and cubic polynomials in the exponent, are shown to be well compatible with the data. Using them for the differential cross-section extrapolation to t=0, and further applying the optical theorem, yields total cross-section estimates of (101.5±2.1)mb and (101.9±2.1)mb, respectively, in agreement with previous TOTEM measurements.
DOI: 10.1088/1748-0221/3/08/s08007
2008
Cited 153 times
The TOTEM Experiment at the CERN Large Hadron Collider
The TOTEM Experiment will measure the total pp cross-section with the luminosity-independent method and study elastic and diffractive scattering at the LHC. To achieve optimum forward coverage for charged particles emitted by the pp collisions in the interaction point IP5, two tracking telescopes, T1 and T2, will be installed on each side in the pseudorapidity region 3.1 ⩽ |η| ⩽ 6.5, and Roman Pot stations will be placed at distances of ±147 m and ±220 m from IP5. Being an independent experiment but technically integrated into CMS, TOTEM will first operate in standalone mode to pursue its own physics programme and at a later stage together with CMS for a common physics programme. This article gives a description of the TOTEM apparatus and its performance.
DOI: 10.1209/0295-5075/95/41001
2011
Cited 139 times
Proton-proton elastic scattering at the LHC energy of \chem{\sqrt{s} = 7\,TeV}
Proton-proton elastic scattering has been measured by the TOTEM experiment at the CERN Large Hadron Collider at in dedicated runs with the Roman Pot detectors placed as close as seven times the transverse beam size (σbeam) from the outgoing beams. After careful study of the accelerator optics and the detector alignment, |t|, the square of four-momentum transferred in the elastic scattering process, has been determined with an uncertainty of . In this letter, first results of the differential cross-section are presented covering a |t|-range from 0.36 to 2.5 GeV2. The differential cross-section in the range 0.36 < |t| < 0.47 GeV2 is described by an exponential with a slope parameter B = (23.6 ± 0.5stat ± 0.4syst) GeV−2, followed by a significant diffractive minimum at |t| = (0.53 ± 0.01stat ± 0.01syst) GeV2. For |t|-values larger than ∼1.5 GeV2, the cross-section exhibits a power law behaviour with an exponent of −7.8 ± 0.3stat ± 0.1syst. When compared to predictions based on the different available models, the data show a strong discriminative power despite the small t-range covered.
DOI: 10.1088/0954-3899/43/11/110201
2016
Cited 108 times
LHC forward physics
The goal of this report is to give a comprehensive overview of the rich field of forward physics, with a special attention to the topics that can be studied at the LHC. The report starts presenting a selection of the Monte Carlo simulation tools currently available, chapter 2, then enters the rich phenomenology of QCD at low, chapter 3, and high, chapter 4, momentum transfer, while the unique scattering conditions of central exclusive production are analyzed in chapter 5. The last two experimental topics, Cosmic Ray and Heavy Ion physics are presented in the chapter 6 and 7 respectively. Chapter 8 is dedicated to the BFKL dynamics, multiparton interactions, and saturation. The report ends with an overview of the forward detectors at LHC. Each chapter is correlated with a comprehensive bibliography, attempting to provide to the interested reader with a wide opportunity for further studies.
DOI: 10.1140/epjc/s10052-016-4399-8
2016
Cited 98 times
Measurement of elastic pp scattering at $$\sqrt{\hbox {s}} = \hbox {8}$$ s = 8 TeV in the Coulomb–nuclear interference region: determination of the $$\mathbf {\rho }$$ ρ -parameter and the total cross-section
The TOTEM experiment at the CERN LHC has measured elastic proton–proton scattering at the centre-of-mass energy $$\sqrt{s}=8\,$$ TeV and four-momentum transfers squared, |t|, from $$6\times 10^{-4}$$ to 0.2 GeV $$^{2}$$ . Near the lower end of the t-interval the differential cross-section is sensitive to the interference between the hadronic and the electromagnetic scattering amplitudes. This article presents the elastic cross-section measurement and the constraints it imposes on the functional forms of the modulus and phase of the hadronic elastic amplitude. The data exclude the traditional Simplified West and Yennie interference formula that requires a constant phase and a purely exponential modulus of the hadronic amplitude. For parametrisations of the hadronic modulus with second- or third-order polynomials in the exponent, the data are compatible with hadronic phase functions giving either central or peripheral behaviour in the impact parameter picture of elastic scattering. In both cases, the $$\rho $$ -parameter is found to be $$0.12 \pm 0.03$$ . The results for the total hadronic cross-section are $$\sigma _\mathrm{tot} = (102.9 \pm 2.3)$$ mb and $$(103.0 \pm 2.3)$$ mb for central and peripheral phase formulations, respectively. Both are consistent with previous TOTEM measurements.
DOI: 10.1140/epjc/s10052-019-6567-0
2019
Cited 88 times
First measurement of elastic, inelastic and total cross-section at $$\sqrt{s}=13$$ s = 13 TeV by TOTEM and overview of cross-section data at LHC energies
The TOTEM collaboration has measured the proton–proton total cross section at $$\sqrt{s}=13~\hbox {TeV}$$ with a luminosity-independent method. Using dedicated $$\beta ^{*}=90~\hbox {m}$$ beam optics, the Roman Pots were inserted very close to the beam. The inelastic scattering rate has been measured by the T1 and T2 telescopes during the same LHC fill. After applying the optical theorem the total proton–proton cross section is $$\sigma _\mathrm{tot}=(110.6~\pm ~3.4$$ ) mb, well in agreement with the extrapolation from lower energies. This method also allows one to derive the luminosity-independent elastic and inelastic cross sections: $$\sigma _\mathrm{el}=(31.0~\pm ~1.7)~\hbox {mb}$$ and $$\sigma _\mathrm{inel}=(79.5~\pm ~1.8)~\hbox {mb}$$ .
DOI: 10.1140/epjc/s10052-019-7223-4
2019
Cited 82 times
First determination of the $${\rho }$$ parameter at $${\sqrt{s} = 13}$$ TeV: probing the existence of a colourless C-odd three-gluon compound state
Abstract The TOTEM experiment at the LHC has performed the first measurement at $$\sqrt{s} = 13\,\mathrm{TeV}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13</mml:mn><mml:mspace /><mml:mi>TeV</mml:mi></mml:mrow></mml:math> of the $$\rho $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>ρ</mml:mi></mml:math> parameter, the real to imaginary ratio of the nuclear elastic scattering amplitude at $$t=0$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>t</mml:mi><mml:mo>=</mml:mo><mml:mn>0</mml:mn></mml:mrow></mml:math> , obtaining the following results: $$\rho = 0.09 \pm 0.01$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>ρ</mml:mi><mml:mo>=</mml:mo><mml:mn>0.09</mml:mn><mml:mo>±</mml:mo><mml:mn>0.01</mml:mn></mml:mrow></mml:math> and $$\rho = 0.10 \pm 0.01$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>ρ</mml:mi><mml:mo>=</mml:mo><mml:mn>0.10</mml:mn><mml:mo>±</mml:mo><mml:mn>0.01</mml:mn></mml:mrow></mml:math> , depending on different physics assumptions and mathematical modelling. The unprecedented precision of the $$\rho $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>ρ</mml:mi></mml:math> measurement, combined with the TOTEM total cross-section measurements in an energy range larger than $$10\,\mathrm{TeV}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>10</mml:mn><mml:mspace /><mml:mi>TeV</mml:mi></mml:mrow></mml:math> (from 2.76 to $$13\,\mathrm{TeV}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>13</mml:mn><mml:mspace /><mml:mi>TeV</mml:mi></mml:mrow></mml:math> ), has implied the exclusion of all the models classified and published by COMPETE. The $$\rho $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>ρ</mml:mi></mml:math> results obtained by TOTEM are compatible with the predictions, from other theoretical models both in the Regge-like framework and in the QCD framework, of a crossing-odd colourless 3-gluon compound state exchange in the t -channel of the proton–proton elastic scattering. On the contrary, if shown that the crossing-odd 3-gluon compound state t -channel exchange is not of importance for the description of elastic scattering, the $$\rho $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>ρ</mml:mi></mml:math> value determined by TOTEM would represent a first evidence of a slowing down of the total cross-section growth at higher energies. The very low-| t | reach allowed also to determine the absolute normalisation using the Coulomb amplitude for the first time at the LHC and obtain a new total proton–proton cross-section measurement $$\sigma _{\mathrm{tot}} = (110.3 \pm 3.5)\,\mathrm{mb}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>σ</mml:mi><mml:mi>tot</mml:mi></mml:msub><mml:mo>=</mml:mo><mml:mrow><mml:mo>(</mml:mo><mml:mn>110.3</mml:mn><mml:mo>±</mml:mo><mml:mn>3.5</mml:mn><mml:mo>)</mml:mo></mml:mrow><mml:mspace /><mml:mi>mb</mml:mi></mml:mrow></mml:math> , completely independent from the previous TOTEM determination. Combining the two TOTEM results yields $$\sigma _{\mathrm{tot}} = (110.5 \pm 2.4)\,\mathrm{mb}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>σ</mml:mi><mml:mi>tot</mml:mi></mml:msub><mml:mo>=</mml:mo><mml:mrow><mml:mo>(</mml:mo><mml:mn>110.5</mml:mn><mml:mo>±</mml:mo><mml:mn>2.4</mml:mn><mml:mo>)</mml:mo></mml:mrow><mml:mspace /><mml:mi>mb</mml:mi></mml:mrow></mml:math> .
DOI: 10.1088/1742-5468/ad138f
2024
Non-equilibrium entanglement asymmetry for discrete groups: the example of the XY spin chain
Abstract Entanglement asymmetry is a novel quantity that, using entanglement methods, measures how much a symmetry is broken in a part of an extended quantum system. So far, it has only been used to characterise the breaking of continuous Abelian symmetries. In this paper, we extend the concept to cyclic <?CDATA $\mathbb{Z}_N$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi mathvariant="double-struck">Z</mml:mi> </mml:mrow> <mml:mi>N</mml:mi> </mml:msub> </mml:math> groups. As an application, we consider the XY spin chain, in which the ground state spontaneously breaks the <?CDATA $\mathbb{Z}_2$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi mathvariant="double-struck">Z</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:math> spin parity symmetry in the ferromagnetic phase. We thoroughly investigate the non-equilibrium dynamics of this symmetry after a global quantum quench, generalising known results for the standard order parameter.
DOI: 10.1209/0295-5075/101/21003
2013
Cited 67 times
Measurement of proton-proton inelastic scattering cross-section at \chem{\sqrt {s} = 7\,{\mathrm {TeV}}}
The TOTEM experiment at the LHC has measured the inelastic proton-proton cross-section at in a β* = 90 m run with low inelastic pile-up. The measurement was based on events with at least one charged particle in the T2 telescope acceptance of 5.3 < |η| < 6.5 in pseudorapidity. Combined with data from the T1 telescope, covering 3.1 < |η| < 4.7, the cross-section for inelastic events with at least one |η| ⩽ 6.5 final-state particle was determined to be (70.5 ± 2.9) mb. This cross-section includes all central diffractive events of which maximally 0.25 mb is estimated to escape the detection of the telescopes. Based on models for low mass diffraction, the total inelastic cross-section was deduced to be (73.7 ± 3.4) mb. An upper limit of 6.31 mb at 95% confidence level on the cross-section for events with diffractive masses below 3.4 GeV was obtained from the difference between the overall inelastic cross-section obtained by TOTEM using elastic scattering and the cross-section for inelastic events with at least one |η| ⩽ 6.5 final-state particle.
DOI: 10.1140/epjc/s10052-019-7346-7
2019
Cited 51 times
Elastic differential cross-section measurement at $$\sqrt{s}=13$$ TeV by TOTEM
Abstract The TOTEM collaboration has measured the elastic proton-proton differential cross section $$\mathrm{d}\sigma /\mathrm{d}t$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>d</mml:mi><mml:mi>σ</mml:mi><mml:mo>/</mml:mo><mml:mi>d</mml:mi><mml:mi>t</mml:mi></mml:mrow></mml:math> at $$\sqrt{s}=13$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13</mml:mn></mml:mrow></mml:math> TeV LHC energy using dedicated $$\beta ^{*}=90$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mi>β</mml:mi><mml:mrow><mml:mrow /><mml:mo>∗</mml:mo></mml:mrow></mml:msup><mml:mo>=</mml:mo><mml:mn>90</mml:mn></mml:mrow></mml:math> m beam optics. The Roman Pot detectors were inserted to 10 $$\sigma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>σ</mml:mi></mml:math> distance from the LHC beam, which allowed the measurement of the range [0.04 GeV $$^{2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow /><mml:mn>2</mml:mn></mml:msup></mml:math> ; 4 GeV $$^{2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow /><mml:mn>2</mml:mn></mml:msup></mml:math> $$]$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>]</mml:mo></mml:math> in four-momentum transfer squared | t |. The efficient data acquisition allowed to collect about 10 $$^{9}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow /><mml:mn>9</mml:mn></mml:msup></mml:math> elastic events to precisely measure the differential cross-section including the diffractive minimum (dip), the subsequent maximum (bump) and the large-| t | tail. The average nuclear slope has been found to be $$B=(20.40 \pm 0.002^{\mathrm{stat}} \pm 0.01^{\mathrm{syst}})~$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>B</mml:mi><mml:mo>=</mml:mo><mml:mo>(</mml:mo><mml:mn>20.40</mml:mn><mml:mo>±</mml:mo><mml:mn>0</mml:mn><mml:mo>.</mml:mo><mml:msup><mml:mn>002</mml:mn><mml:mi>stat</mml:mi></mml:msup><mml:mo>±</mml:mo><mml:mn>0</mml:mn><mml:mo>.</mml:mo><mml:msup><mml:mn>01</mml:mn><mml:mi>syst</mml:mi></mml:msup><mml:mo>)</mml:mo><mml:mspace /></mml:mrow></mml:math> GeV $$^{-2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow /><mml:mrow><mml:mo>-</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math> in the | t |-range 0.04–0.2 GeV $$^{2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow /><mml:mn>2</mml:mn></mml:msup></mml:math> . The dip position is $$|t_{\mathrm{dip}}|=(0.47 \pm 0.004^{\mathrm{stat}} \pm 0.01^{\mathrm{syst}})~$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mrow><mml:mo>|</mml:mo></mml:mrow><mml:msub><mml:mi>t</mml:mi><mml:mi>dip</mml:mi></mml:msub><mml:mrow><mml:mo>|</mml:mo><mml:mo>=</mml:mo></mml:mrow><mml:mrow><mml:mo>(</mml:mo><mml:mn>0.47</mml:mn><mml:mo>±</mml:mo><mml:mn>0</mml:mn><mml:mo>.</mml:mo><mml:msup><mml:mn>004</mml:mn><mml:mi>stat</mml:mi></mml:msup><mml:mo>±</mml:mo><mml:mn>0</mml:mn><mml:mo>.</mml:mo><mml:msup><mml:mn>01</mml:mn><mml:mi>syst</mml:mi></mml:msup><mml:mo>)</mml:mo></mml:mrow><mml:mspace /></mml:mrow></mml:math> GeV $$^{2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow /><mml:mn>2</mml:mn></mml:msup></mml:math> . The differential cross section ratio at the bump vs. at the dip $$R=1.77\pm 0.01^{\mathrm{stat}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>R</mml:mi><mml:mo>=</mml:mo><mml:mn>1.77</mml:mn><mml:mo>±</mml:mo><mml:mn>0</mml:mn><mml:mo>.</mml:mo><mml:msup><mml:mn>01</mml:mn><mml:mi>stat</mml:mi></mml:msup></mml:mrow></mml:math> has been measured with high precision. The series of TOTEM elastic pp measurements show that the dip is a permanent feature of the pp differential cross-section at the TeV scale.
DOI: 10.1140/epjc/s10052-020-7654-y
2020
Cited 38 times
Elastic differential cross-section $${\mathrm{d}}\sigma /{\mathrm{d}}t$$ at $$\sqrt{s}=2.76\hbox { TeV}$$ and implications on the existence of a colourless C-odd three-gluon compound state
Abstract The proton–proton elastic differential cross section $${\mathrm{d}}\sigma /{\mathrm{d}}t$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>d</mml:mi><mml:mi>σ</mml:mi><mml:mo>/</mml:mo><mml:mi>d</mml:mi><mml:mi>t</mml:mi></mml:mrow></mml:math> has been measured by the TOTEM experiment at $$\sqrt{s}=2.76\hbox { TeV}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>2.76</mml:mn><mml:mspace /><mml:mtext>TeV</mml:mtext></mml:mrow></mml:math> energy with $$\beta ^{*}=11\hbox { m}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mi>β</mml:mi><mml:mrow><mml:mrow /><mml:mo>∗</mml:mo></mml:mrow></mml:msup><mml:mo>=</mml:mo><mml:mn>11</mml:mn><mml:mspace /><mml:mtext>m</mml:mtext></mml:mrow></mml:math> beam optics. The Roman Pots were inserted to 13 times the transverse beam size from the beam, which allowed to measure the differential cross-section of elastic scattering in a range of the squared four-momentum transfer (| t |) from 0.36 to $$0.74\hbox { GeV}^{2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>0.74</mml:mn><mml:mspace /><mml:msup><mml:mtext>GeV</mml:mtext><mml:mn>2</mml:mn></mml:msup></mml:mrow></mml:math> . The differential cross-section can be described with an exponential in the | t |-range between 0.36 and $$0.54\hbox { GeV}^{2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>0.54</mml:mn><mml:mspace /><mml:msup><mml:mtext>GeV</mml:mtext><mml:mn>2</mml:mn></mml:msup></mml:mrow></mml:math> , followed by a diffractive minimum (dip) at $$|t_{\mathrm{dip}}|=(0.61\pm 0.03)\hbox { GeV}^{2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mrow><mml:mo>|</mml:mo></mml:mrow><mml:msub><mml:mi>t</mml:mi><mml:mi>dip</mml:mi></mml:msub><mml:mrow><mml:mo>|</mml:mo><mml:mo>=</mml:mo><mml:mrow><mml:mo>(</mml:mo><mml:mn>0.61</mml:mn><mml:mo>±</mml:mo><mml:mn>0.03</mml:mn><mml:mo>)</mml:mo></mml:mrow><mml:mspace /></mml:mrow><mml:msup><mml:mtext>GeV</mml:mtext><mml:mn>2</mml:mn></mml:msup></mml:mrow></mml:math> and a subsequent maximum (bump). The ratio of the $${\mathrm{d}}\sigma /{\mathrm{d}}t$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>d</mml:mi><mml:mi>σ</mml:mi><mml:mo>/</mml:mo><mml:mi>d</mml:mi><mml:mi>t</mml:mi></mml:mrow></mml:math> at the bump and at the dip is $$1.7\pm 0.2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>1.7</mml:mn><mml:mo>±</mml:mo><mml:mn>0.2</mml:mn></mml:mrow></mml:math> . When compared to the proton–antiproton measurement of the D0 experiment at $$\sqrt{s} = 1.96\hbox { TeV}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>1.96</mml:mn><mml:mspace /><mml:mtext>TeV</mml:mtext></mml:mrow></mml:math> , a significant difference can be observed. Under the condition that the effects due to the energy difference between TOTEM and D0 can be neglected, the result provides evidence for the exchange of a colourless C-odd three-gluon compound state in the t -channel of the proton–proton and proton–antiproton elastic scattering.
DOI: 10.1103/physrevlett.111.262001
2013
Cited 38 times
Double Diffractive Cross-Section Measurement in the Forward Region at the LHC
The first double diffractive cross-section measurement in the very forward region has been carried out by the TOTEM experiment at the LHC with center-of-mass energy of sqrt(s)=7 TeV. By utilizing the very forward TOTEM tracking detectors T1 and T2, which extend up to |eta|=6.5, a clean sample of double diffractive pp events was extracted. From these events, we measured the cross-section sigma_DD =(116 +- 25) mub for events where both diffractive systems have 4.7 <|eta|_min < 6.5 .
DOI: 10.1140/epja/i2004-10006-0
2004
Cited 55 times
Non-extensive resonant reaction rates in astrophysical plasmas
We study two different physical scenarios of thermonuclear reactions in stellar plasmas proceeding through a narrow resonance at low energy or through the low-energy wing of a wide resonance at high energy. Correspondingly, we derive two approximate analytical formulae in order to calculate thermonuclear resonant reaction rates inside very coupled and non-ideal astrophysical plasmas in which non-extensive effects are likely to arise. Our results are presented as simple first-order corrective factors that generalize the well-known classical rates obtained in the framework of Maxwell-Boltzmann statistical mechanics. As a possible application of our results, we calculate the dependence of the total corrective factor with respect to the energy at which the resonance is located, in an extremely dense and non-ideal carbon plasma.
DOI: 10.1209/0295-5075/98/31002
2012
Cited 34 times
Measurement of the forward charged-particle pseudorapidity density in <i>pp</i> collisions at √s = 7 TeV with the TOTEM experiment
The TOTEM experiment has measured the charged-particle pseudorapidity density dNch/dη in pp collisions at for 5.3<|η|<6.4 in events with at least one charged particle with transverse momentum above 40 MeV/c in this pseudorapidity range. This extends the analogous measurement performed by the other LHC experiments to the previously unexplored forward η region. The measurement refers to more than 99% of non-diffractive processes and to single and double diffractive processes with diffractive masses above ∼3.4 GeV/c2, corresponding to about 95% of the total inelastic cross-section. The dNch/dη has been found to decrease with |η|, from 3.84 ± 0.01(stat) ± 0.37(syst) at |η|=5.375 to 2.38±0.01(stat)±0.21(syst) at |η|=6.375. Several MC generators have been compared to data; none of them has been found to fully describe the measurement.
DOI: 10.1143/ptps.193.180
2012
Cited 24 times
Elastic Scattering and Total Cross-Section in p+p Reactions
Proton-proton elastic scattering has been measured by the TOTEM experiment at the CERN Large Hadron Collider at √s = 7 TeV in special runs with the Roman Pot detectors placed as close to the outgoing beam as seven times the transverse beam size. The differential cross-section measurements are reported in the |t|-range of 0.36 to 2.5 GeV2. Extending the range of data to low t values from 0.02 to 0.33 GeV2, and utilizing the luminosity measurements of CMS, the total proton-proton cross section at √s = 7 TeV is measured to be (98.3 ±0.2stat ±2.8syst) mb.
DOI: 10.1142/s0217751x13300469
2013
Cited 23 times
PERFORMANCE OF THE TOTEM DETECTORS AT THE LHC
The TOTEM Experiment is designed to measure the total proton-proton cross-section with the luminosity-independent method and to study elastic and diffractive pp scattering at the LHC. To achieve optimum forward coverage for charged particles emitted by the pp collisions in the interaction point IP5, two tracking telescopes, T1 and T2, are installed on each side of the IP in the pseudorapidity region 3.1 < = |eta | < = 6.5, and special movable beam-pipe insertions - called Roman Pots (RP) - are placed at distances of +- 147 m and +- 220 m from IP5. This article describes in detail the working of the TOTEM detector to produce physics results in the first three years of operation and data taking at the LHC.
DOI: 10.1088/1748-0221/12/03/p03007
2017
Cited 22 times
Diamond detectors for the TOTEM timing upgrade
This paper describes the design and the performance of the timing detector developed by the TOTEM Collaboration for the Roman Pots (RPs) to measure the Time-Of-Flight (TOF) of the protons produced in central diffractive interactions at the LHC . The measurement of the TOF of the protons allows the determination of the longitudinal position of the proton interaction vertex and its association with one of the vertices reconstructed by the CMS detectors. The TOF detector is based on single crystal Chemical Vapor Deposition (scCVD) diamond plates and is designed to measure the protons TOF with about 50 ps time precision. This upgrade to the TOTEM apparatus will be used in the LHC run 2 and will tag the central diffractive events up to an interaction pileup of about 1. A dedicated fast and low noise electronics for the signal amplification has been developed. The digitization of the diamond signal is performed by sampling the waveform. After introducing the physics studies that will most profit from the addition of these new detectors, we discuss in detail the optimization and the performance of the first TOF detector installed in the LHC in November 2015.
DOI: 10.1109/tns.2005.856910
2005
Cited 32 times
Planar edgeless silicon detectors for the TOTEM experiment
Silicon detectors for the Roman Pots of the large hadron collider TOTEM experiment aim for full sensitivity at the edge where a terminating structure is required for electrical stability. This work provides an innovative approach reducing the conventional width of the terminating structure to less than 100 microns, still using standard planar fabrication technology. The objective of this new development is to decouple the electric behaviour of the surface from the sensitive volume within tens of microns. The explanation of the basic principle of this new approach together with the experimental confirmation via electric measurements and beam test are presented in this paper, demonstrating that silicon detectors with this new terminating structure are fully operational and efficient to under 60 microns from the die cut.
DOI: 10.1016/j.nuclphysa.2007.02.007
2007
Cited 30 times
production in antiproton–nucleus collisions at
We analyse in detail a recently proposed technique for producing high rates of Ξ− hyperons from p¯ beams and for their slowing down until rest, as planned for the Double-Hypernuclei experiment at the future HESR-GSI facility. We describe the Monte Carlo event generator that we developed for this purpose, and discuss the numerical results obtained within our model, in connection with the expected performances and operation modes of the HESR ring.
DOI: 10.1140/epjc/s10052-015-3343-7
2015
Cited 17 times
Measurement of the forward charged particle pseudorapidity density in pp collisions at $$\sqrt{s} = 8$$ s = 8 TeV using a displaced interaction point
The pseudorapidity density of charged particles dN $$_{ ch }$$ /d $$\eta $$ is measured by the TOTEM experiment in proton–proton collisions at $$\sqrt{s} = 8$$ TeV within the range $$3.9<\eta <4.7$$ and $$-6.95<\eta <-6.9$$ . Data were collected in a low intensity LHC run with collisions occurring at a distance of 11.25 m from the nominal interaction point. The data sample is expected to include 96–97 % of the inelastic proton–proton interactions. The measurement reported here considers charged particles with $$p_T>0$$ MeV/c, produced in inelastic interactions with at least one charged particle in $$-7<\eta <-6$$ or $$3.7<\eta <4.8$$ . The dN $$_{ ch }$$ /d $$\eta $$ has been found to decrease with $$|\eta |$$ , from 5.11 $$\pm $$ 0.73 at $$\eta =3.95$$ to 1.81 $$\pm $$ 0.56 at $$\eta =-$$ 6.925. Several Monte Carlo generators are compared to the data and are found to be within the systematic uncertainty of the measurement.
DOI: 10.48550/arxiv.2404.07068
2024
Entanglement entropy in the ground state of non-interacting massless Dirac fermions in dimension one
We present a novel proof of a formula of Casini and Huerta for the entanglement entropy of the ground state of non-interacting massless Dirac fermions in dimension one localized to (a union of) intervals and generalize it to the case of R\'enyi entropies. At first, we prove that these entropies are well-defined for non-intersecting intervals. This is accomplished by an inequality of Alexander V.~Sobolev. Then we compute this entropy using a trace formula for Wiener--Hopf operators by Harold Widom. For intersecting intervals, we discuss an extended entropy formula of Casini and Huerta and support this with a proof for polynomial test functions (instead of entropy).
DOI: 10.1016/j.nima.2006.12.030
2007
Cited 25 times
Performance of HPGe detectors in high magnetic fields
A new generation of high-resolution hypernuclear γ-spectroscopy experiments with high-purity germanium detectors (HPGe) are presently designed at the FINUDA spectrometer at DAΦNE, the Frascati φ-factory, and at P¯ANDA, the p¯p hadron spectrometer at the future FAIR facility. Both, the FINUDA and P¯ANDA spectrometers are built around the target region covering a large solid angle. To maximise the detection efficiency the HPGe detectors have to be located near the target, and therefore they have to be operated in strong magnetic fields (B≈1T). The performance of HPGe detectors in such an environment has not been well investigated so far. In the present work VEGA and EUROBALL Cluster HPGe detectors were tested in the field provided by the ALADiN magnet at GSI. No significant degradation of the energy resolution was found, and a change in the rise time distribution of the pulses from preamplifiers was observed. A correlation between rise time and pulse height was observed and is used to correct the measured energy, recovering the energy resolution almost completely. Moreover, no problems in the electronics due to the magnetic field were observed.
DOI: 10.1088/1367-2630/16/10/103041
2014
Cited 16 times
LHC optics measurement with proton tracks detected by the Roman pots of the TOTEM experiment
Precise knowledge of the beam optics at the LHC is crucial to fulfil the physics goals of the TOTEM experiment, where the kinematics of the scattered protons is reconstructed with the near-beam telescopes -- so-called Roman Pots (RP). Before being detected, the protons' trajectories are influenced by the magnetic fields of the accelerator lattice. Thus precise understanding of the proton transport is of key importance for the experiment. A novel method of optics evaluation is proposed which exploits kinematical distributions of elastically scattered protons observed in the RPs. Theoretical predictions, as well as Monte Carlo studies, show that the residual uncertainty of this optics estimation method is smaller than 0.25 percent.
DOI: 10.1140/epjc/s10052-022-10065-x
2022
Cited 6 times
Characterisation of the dip-bump structure observed in proton–proton elastic scattering at $$\sqrt{s}$$ = 8 TeV
Abstract The TOTEM collaboration at the CERN LHC has measured the differential cross-section of elastic proton–proton scattering at $$\sqrt{s} = 8\,\mathrm{TeV}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>8</mml:mn> <mml:mspace /> <mml:mi>TeV</mml:mi> </mml:mrow> </mml:math> in the squared four-momentum transfer range $$0.2\,\mathrm{GeV^{2}}&lt; |t| &lt; 1.9\,\mathrm{GeV^{2}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>0.2</mml:mn> <mml:mspace /> <mml:msup> <mml:mi>GeV</mml:mi> <mml:mn>2</mml:mn> </mml:msup> <mml:mo>&lt;</mml:mo> <mml:mrow> <mml:mo>|</mml:mo> <mml:mi>t</mml:mi> <mml:mo>|</mml:mo> </mml:mrow> <mml:mo>&lt;</mml:mo> <mml:mn>1.9</mml:mn> <mml:mspace /> <mml:msup> <mml:mi>GeV</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:math> . This interval includes the structure with a diffractive minimum (“dip”) and a secondary maximum (“bump”) that has also been observed at all other LHC energies, where measurements were made. A detailed characterisation of this structure for $$\sqrt{s} = 8\,\mathrm{TeV}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>8</mml:mn> <mml:mspace /> <mml:mi>TeV</mml:mi> </mml:mrow> </mml:math> yields the positions, $$|t|_{\mathrm{dip}} = (0.521 \pm 0.007)\,\mathrm{GeV^2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mo>|</mml:mo> <mml:mi>t</mml:mi> <mml:mo>|</mml:mo> </mml:mrow> <mml:mi>dip</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>0.521</mml:mn> <mml:mo>±</mml:mo> <mml:mn>0.007</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mspace /> <mml:msup> <mml:mi>GeV</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:math> and $$|t|_{\mathrm{bump}} = (0.695 \pm 0.026)\,\mathrm{GeV^2}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mo>|</mml:mo> <mml:mi>t</mml:mi> <mml:mo>|</mml:mo> </mml:mrow> <mml:mi>bump</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>0.695</mml:mn> <mml:mo>±</mml:mo> <mml:mn>0.026</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mspace /> <mml:msup> <mml:mi>GeV</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:math> , as well as the cross-section values, $$\left. {\mathrm{d}\sigma /\mathrm{d}t}\right| _{\mathrm{dip}} = (15.1 \pm 2.5)\,\mathrm{{\mu b/GeV^2}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mfenced> <mml:mrow> <mml:mi>d</mml:mi> <mml:mi>σ</mml:mi> <mml:mo>/</mml:mo> <mml:mi>d</mml:mi> <mml:mi>t</mml:mi> </mml:mrow> </mml:mfenced> <mml:mi>dip</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>15.1</mml:mn> <mml:mo>±</mml:mo> <mml:mn>2.5</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mspace /> <mml:mrow> <mml:mi>μ</mml:mi> <mml:mi>b</mml:mi> <mml:mo>/</mml:mo> <mml:msup> <mml:mi>GeV</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:mrow> </mml:math> and $$\left. {\mathrm{d}\sigma /\mathrm{d}t}\right| _{\mathrm{bump}} = (29.7 \pm 1.8)\,\mathrm{{\mu b/GeV^2}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mfenced> <mml:mrow> <mml:mi>d</mml:mi> <mml:mi>σ</mml:mi> <mml:mo>/</mml:mo> <mml:mi>d</mml:mi> <mml:mi>t</mml:mi> </mml:mrow> </mml:mfenced> <mml:mi>bump</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>29.7</mml:mn> <mml:mo>±</mml:mo> <mml:mn>1.8</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mspace /> <mml:mrow> <mml:mi>μ</mml:mi> <mml:mi>b</mml:mi> <mml:mo>/</mml:mo> <mml:msup> <mml:mi>GeV</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:mrow> </mml:math> , for the dip and the bump, respectively.
DOI: 10.48550/arxiv.hep-ph/0601013
2006
Cited 22 times
HERA and the LHC - A workshop on the implications of HERA for LHC physics: Proceedings - Part B
The HERA electron--proton collider has collected 100 pb$^{-1}$ of data since its start-up in 1992, and recently moved into a high-luminosity operation mode, with upgraded detectors, aiming to increase the total integrated luminosity per experiment to more than 500 pb$^{-1}$. HERA has been a machine of excellence for the study of QCD and the structure of the proton. The Large Hadron Collider (LHC), which will collide protons with a centre-of-mass energy of 14 TeV, will be completed at CERN in 2007. The main mission of the LHC is to discover and study the mechanisms of electroweak symmetry breaking, possibly via the discovery of the Higgs particle, and search for new physics in the TeV energy scale, such as supersymmetry or extra dimensions. Besides these goals, the LHC will also make a substantial number of precision measurements and will offer a new regime to study the strong force via perturbative QCD processes and diffraction. For the full LHC physics programme a good understanding of QCD phenomena and the structure function of the proton is essential. Therefore, in March 2004, a one-year-long workshop started to study the implications of HERA on LHC physics. This included proposing new measurements to be made at HERA, extracting the maximum information from the available data, and developing/improving the theoretical and experimental tools. This report summarizes the results achieved during this workshop.
DOI: 10.1016/j.nima.2008.04.017
2008
Cited 20 times
Resolution, efficiency and stability of HPGe detector operating in a magnetic field at various gamma-ray energies
The use of High Purity Germanium detectors (HPGe) has been planned in some future experiments of hadronic physics. The crystals will be located close to large spectrometers where the magnetic fringing field will not be negligible and their performances might change. Moreover high precision is required in these experiments. The contribution of magnetic field presence and long term measurements is unique. In this paper the results of systematic measurements of the resolution, stability and efficiency of a crystal operating inside a magnetic field of 0.8 T, using radioactive sources in the energy range from 0.08 to 1.33 MeV, are reported. The measurements have been repeated during several months in order to test if any permanent damage occurred. The resolution at 1.117 and 1.332 MeV gamma-rays from a 60Co source has been measured at different magnetic fields in the range of 0–0.8 T and the results are compared with the previous data.
DOI: 10.1103/physreva.81.062503
2010
Cited 17 times
Isotope shift of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>1</mml:mn><mml:mi>s</mml:mi><mml:mn>2</mml:mn><mml:mi>p</mml:mi><mml:mi> </mml:mi><mml:msup><mml:mrow /><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msup><mml:msub><mml:mi>P</mml:mi><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>–<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>1</mml:mn><mml:mi>s</mml:mi><mml:mn>2</…
Heavy He-like ions are considered to be promising candidates for atomic parity-nonconservation (PNC) studies, thanks to their relatively simple atomic structure and the significant mixing between the almost degenerate (for the atomic numbers $Z~64$ and $Z~91$) opposite-parity levels $1s2s {}^{1}{S}_{0}$ and $1s2p {}^{3}{P}_{0}$. A number of experiments exploiting this level mixing have been proposed, and their implementation requires a precise knowledge of the $2 {}^{3}{P}_{0}$--$2 {}^{1}{S}_{0}$ energy splitting for different nuclear charges and isotopes. In this paper we performed a theoretical analysis of the level splitting, employing the relativistic many-body perturbation theory and including QED corrections for all isotopes in the intervals $54\ensuremath{\leqslant}Z\ensuremath{\leqslant}71$ and $86\ensuremath{\leqslant}Z\ensuremath{\leqslant}93$. Possible candidates for future experimental PNC studies are discussed.
DOI: 10.1016/j.nima.2009.08.083
2010
Cited 16 times
The TOTEM detector at LHC
Abstract The TOTEM experiment, small in size compared to the others at the LHC, is dedicated to the measurement of the total proton–proton cross-sections with a luminosity-independent method and to the study of elastic and diffractive scattering at the LHC. To achieve optimum forward coverage for charged particles emitted by the pp collisions in the IP5 interaction point, two tracking telescopes, T1 and T2, will be installed on each side in the pseudo-rapidity region between 3.1 and 6.5, and Roman Pot stations will be placed at distances of 147 and 220 m from IP5. The telescope closest to the interaction point (T1, centred at z=9 m) consists of Cathode Strip Chambers (CSC), while the second one (T2, centred at 13.5 m), makes use of Gas Electron Multipliers (GEM). The proton detectors in the Roman Pots are silicon devices designed by TOTEM with the specific objective of reducing down to a few tens of microns the insensitive area at the edge. High efficiency as close as possible to the physical detector boundary is an essential feature. It maximizes the experimental acceptance for protons scattered elastically or interactively at polar angles down to a few micro-radians at IP5. To measure protons at the lowest possible emission angles, special beam optics have been conceived to optimize proton detection in terms of acceptance and resolution. The read-out of all TOTEM subsystems is based on the custom-developed digital VFAT chip with trigger capability.
DOI: 10.1063/1.3601401
2011
Cited 15 times
First data from TOTEM experiment at LHC
The TOTEM experiment at the LHC is mainly dedicated to the measurement of the total proton‐proton cross section, elastic scattering and to the study of the diffractive processes. This contribution reviews the physics goals of the experiment, the status of the experimental apparatus and of the analysis of the first data from the LHC.
DOI: 10.1016/j.nima.2006.01.111
2006
Cited 21 times
Final size planar edgeless silicon detectors for the TOTEM experiment
The TOTEM experiment will detect leading protons scattered in angles of microradians from the interaction point at the large hadron collider. This will be achieved using detectors with a minimized dead area at the edge. The collaboration has developed an innovative structure at the detector edge reducing the conventional dead width to less than 100 μm, still using standard planar fabrication technology. In this new development, the current of the surface is decoupled from the sensitive volume current within a few tens of micrometers. The basic working principle is explained in this paper. Final size detectors have been produced using this approach. The current–voltage and current–temperature characteristics of the detectors were studied and the detectors were successfully tested in a coasting beam experiment.
DOI: 10.1109/tns.2009.2013951
2009
Cited 16 times
3D Active Edge Silicon Detector Tests With 120 GeV Muons
3D detectors with electrodes penetrating through the silicon wafer and covering the edges were tested in the SPS beam line X5 at CERN in autumn 2003. Detector parameters including efficiency, signal-to-noise ratio, and edge sensitivity were measured using a silicon telescope as a reference system. The measured sensitive width and the known silicon width were equal within less than 10 mum.
DOI: 10.1103/physreva.83.052518
2011
Cited 14 times
Hyperfine transitions in He-like ions as a tool for nuclear-spin-dependent parity-nonconservation studies
In this paper a scheme is proposed for measuring nuclear-spin-dependent parity-nonconservation effects in highly charged ions. The idea is to employ circularly polarized laser light for inducing the transition between the level $(1s2s){}^{1}{S}_{0}$ and the hyperfine sublevels of $(1s2s){}^{3}{S}_{1}$ in He-like ions with nonzero nuclear spin. We argue that an interference between the allowed magnetic dipole $M1$ and the parity-violating electric dipole $E1$ decay channel leads to an observable asymmetry of order ${10}^{\ensuremath{-}7}$ in the transition cross section, in the atomic range $28\ensuremath{\leqslant}Z\ensuremath{\leqslant}35$. Experimental requirements for asymmetry measurements are discussed in the case of He-like ${}_{34}^{77}$Se.
DOI: 10.48550/arxiv.2307.06902
2023
Non-equilibrium entanglement asymmetry for discrete groups: the example of the XY spin chain
The entanglement asymmetry is a novel quantity that, using entanglement methods, measures how much a symmetry is broken in a part of an extended quantum system. So far it has only been used to characterise the breaking of continuous Abelian symmetries. In this paper, we extend the concept to cyclic $\mathbb{Z}_N$ groups. As an application, we consider the XY spin chain, in which the ground state spontaneously breaks the $\mathbb{Z}_2$ spin parity symmetry in the ferromagnetic phase. We thoroughly investigate the non-equilibrium dynamics of this symmetry after a global quantum quench, generalising known results for the standard order parameter.
DOI: 10.1088/0953-2048/12/11/314
1999
Cited 20 times
Source optimization for magnetron sputter-deposition of NbTiN tuning elements for SIS THz detectors
NbTiN is one of the most promising materials for use in the tuning circuits of Nb-based SIS mixers for operating frequencies above the gap frequency of Nb (700 GHz). Device development requires stable and reproducible film properties. In this manuscript we compare the properties of NbTiN films obtained with a sputtering source using balanced and unbalanced magnetic trap configurations. This experiment shows that reducing the effectiveness of the magnetic trap by changing the magnet configuration is equivalent to reducing the sputtering pressure. We also show that it is possible to optimize the configuration of the magnetron magnets to produce stable and reproducible NbTiN films under the same gas pressure and applied power throughout the target lifetime.
DOI: 10.1140/epjcd/s2004-04-024-8
2004
Cited 13 times
The TOTEM experiment
DOI: 10.48550/arxiv.1306.5413
2013
Cited 7 times
Summary of the Workshop on Multi-Parton Interactions (MPI@LHC 2012)
With short resumes and highlights the discussions in the different working groups of the workshop MPI@LHC 2012 is documented.
2004
Cited 12 times
TOTEM: Technical design report - Addendum. Total cross section, elastic scattering and diffraction dissociation at the Large Hadron Collider at CERN
DOI: 10.48550/arxiv.hep-ph/0601012
2006
Cited 10 times
HERA and the LHC - A workshop on the implications of HERA for LHC physics: Proceedings - Part A
The HERA electron--proton collider has collected 100 pb$^{-1}$ of data since its start-up in 1992, and recently moved into a high-luminosity operation mode, with upgraded detectors, aiming to increase the total integrated luminosity per experiment to more than 500 pb$^{-1}$. HERA has been a machine of excellence for the study of QCD and the structure of the proton. The Large Hadron Collider (LHC), which will collide protons with a centre-of-mass energy of 14 TeV, will be completed at CERN in 2007. The main mission of the LHC is to discover and study the mechanisms of electroweak symmetry breaking, possibly via the discovery of the Higgs particle, and search for new physics in the TeV energy scale, such as supersymmetry or extra dimensions. Besides these goals, the LHC will also make a substantial number of precision measurements and will offer a new regime to study the strong force via perturbative QCD processes and diffraction. For the full LHC physics programme a good understanding of QCD phenomena and the structure function of the proton is essential. Therefore, in March 2004, a one-year-long workshop started to study the implications of HERA on LHC physics. This included proposing new measurements to be made at HERA, extracting the maximum information from the available data, and developing/improving the theoretical and experimental tools. This report summarizes the results achieved during this workshop.
DOI: 10.48550/arxiv.1712.06153
2017
Cited 6 times
First measurement of elastic, inelastic and total cross-section at $\sqrt{s}=13$ TeV by TOTEM and overview of cross-section data at LHC energies
The TOTEM collaboration has measured the proton-proton total cross section at $\sqrt{s}=13$ TeV with a luminosity-independent method. Using dedicated $β^{*}=90$ m beam optics, the Roman Pots were inserted very close to the beam. The inelastic scattering rate has been measured by the T1 and T2 telescopes during the same LHC fill. After applying the optical theorem the total proton-proton cross section is $σ_{\rm tot}=(110.6 \pm 3.4$) mb, well in agreement with the extrapolation from lower energies. This method also allows one to derive the luminosity-independent elastic and inelastic cross sections: $σ_{\rm el} = (31.0 \pm 1.7)$ mb and $σ_{\rm inel} = (79.5 \pm 1.8)$ mb.
DOI: 10.1103/physreve.71.026408
2005
Cited 10 times
Collisional cross sections and momentum distributions in astrophysical plasmas: Dynamics and statistical mechanics link
We show that in stellar core plasmas, the one-body momentum distribution function is strongly dependent, at least in the high velocity regime, on the microscopic dynamics of ion elastic collisions and therefore on the effective collisional cross sections if a random force field is present. We take into account two cross sections describing ion-dipole and ion-ion screened interactions. Furthermore, we introduce a third unusual cross section to link statistical distributions and a quantum effect originated by the energy-momentum uncertainty owing to many-body collisions. We also propose a possible physical interpretation in terms of a tidal-like force. We show that each collisional cross section gives rise to a slight peculiar correction on the Maxwellian momentum distribution function in a well defined velocity interval. We also find a possible link between microscopic dynamics of ions and statistical mechanics in interpreting our results in the framework of nonextensive statistical mechanics.
DOI: 10.1016/j.physa.2004.04.043
2004
Cited 10 times
Temperature dependence of modified CNO nuclear reaction rates in dense stellar plasmas
We study the dependence of the CNO nuclear reaction rates on temperature, in the range of 107–108K, the typical range of temperature evolution from a Sun-like star towards a white dwarf. We show that the temperature dependence of the CNO nuclear reaction rates is strongly affected by the presence of non-extensive statistical effects in the dense stellar core. A very small deviation from the Maxwell–Boltzmann particle distribution implies a relevant enhancement of the CNO reaction rate and could explain the presence of heavier elements (e.g. Fe, Mg) in the final composition of a white dwarf core. Such a behavior is consistent with the recent experimental upper limit to the fraction of energy that the Sun produces via the CNO fusion cycle.
2006
Cited 9 times
Prospects for Diffractive and Forward Physics at the LHC
The CMS and TOTEM experiments intend to carry out a joint diffractive/forward physics program with an unprecedented rapidity coverage. The present document outlines some aspects of such a physics program, which spans from the investigation of the low-x structure of the proton to the diffractive production of a SM or MSSM Higgs boson.
DOI: 10.1088/1742-6596/194/1/012024
2009
Cited 7 times
Low-energy collisions with atomic and molecular ions in a photocathode electron target
Dielectronic recombination of highly charged atomic ions and dissociative recombination of molecular ions have been investigated using fast ion beams merged with cold intense electron beams (down to <1meV beam temperature) from a GaAs photocathode. For beryllium-like germanium ions (Ge28+) isolated fine structure Rydberg resonances (n = 9 and 14) were observed at <0.2eV revealing configuration interaction with triply excited resonances and appearing as candidates for deriving radiative shifts of the 2s2-2s2p(3P0) excitation energy. For hydrogen fluoride ions (HF+) dissociative recombination with the cold electrons, producing n = 2 hydrogen atoms, was seen to occur for specific excited initial rotational levels. These levels were identified by their fragment energies down to about 4meV and it is envisaged to measure these energies with sub-meV accuracy.
DOI: 10.1088/1748-0221/8/06/p06009
2013
Cited 5 times
Performance of almost edgeless silicon detectors in CTS and 3D-planar technologies
The physics programme of the TOTEM experiment requires the detection of very forward protons scattered by only a few microradians out of the LHC beams. For this purpose, stacks of planar Silicon detectors have been mounted in moveable near-beam telescopes (Roman Pots) located along the beamline on both sides of the interaction point. In order to maximise the proton acceptance close to the beams, the dead space at the detector edge had to be minimised. During the detector prototyping phase, different sensor technologies and designs have been explored. A reduction of the dead space to less than 50 μm has been accomplished with two novel silicon detector technologies: one with the Current Terminating Structure (CTS) design and one based on the 3D edge manufacturing. This paper describes performance studies on prototypes of these detectors, carried out in 2004 in a fixed-target muon beam at CERN's SPS accelerator. In particular, the efficiency and accuracy in the vicinity of the beam-facing edges are discussed.
2018
Cited 5 times
First determination of the $\rho $ parameter at $\sqrt{s} = 13$ TeV -- probing the existence of a colourless three-gluon bound state
The TOTEM experiment at the LHC has performed the first measurement at $\sqrt{s} = 13$ TeV of the $\rho$ parameter, the real to imaginary ratio of the nuclear elastic scattering amplitude at $t=0$, obtaining the following results: $\rho = 0.09 \pm 0.01$ and $\rho = 0.10 \pm 0.01$, depending on different physics assumptions and mathematical modelling. The unprecedented precision of the $\rho$ measurement, combined with the TOTEM total cross-section measurements in an energy range larger than 10 TeV (from 2.76 to 13 TeV), has implied the exclusion of all the models classified and published by COMPETE. The $\rho$ results obtained by TOTEM are compatible with the predictions, from alternative theoretical models both in the Regge-like framework and in the QCD framework, of a colourless 3-gluon bound state exchange in the $t$-channel of the proton-proton elastic scattering. On the contrary, if shown that the 3-gluon bound state $t$-channel exchange is not of importance for the description of elastic scattering, the $\rho$ value determined by TOTEM would represent a first evidence of a slowing down of the total cross-section growth at higher energies. The very low-$|t|$ reach allowed also to determine the absolute normalisation using the Coulomb amplitude for the first time at the LHC and obtain a new total proton-proton cross-section measurement $\sigma_{tot} = 110.3 \pm 3.5$ mb, completely independent from the previous TOTEM determination. Combining the two TOTEM results yields $\sigma_{tot} = 110.5 \pm 2.4$ mb.
DOI: 10.1016/j.physleta.2005.01.011
2005
Cited 7 times
Metastable and stable equilibrium states of stellar electron-nuclear plasmas
By minimizing free energy density, we show that the stellar core of a hydrogen burning star is not in a global thermodynamical equilibrium unless density, temperature, mass and composition assume given values. The core (as the solar interior) can more appropriately be viewed as a metastable state with very long lifetime. Slightly non-extensive distribution function could be the natural distribution for a weakly non-ideal plasma like a stellar core and represents a more appropriate approximation to this system than a Maxwellian distribution, without affecting bulk properties of stars.
DOI: 10.1109/nssmic.2004.1462661
2005
Cited 7 times
An object-oriented simulation program for CMS
The CMS detector simulation package, OSCAR, is based on the Geant4 simulation toolkit and the CMS object-oriented framework for simulation and reconstruction. Geant4 provides a rich set of physics processes describing in detail electromagnetic and hadronic interactions. It also provides the tools for the implementation of the full CMS detector geometry and the interfaces required for recovering information from the particle tracking in the detectors. This functionality is interfaced to the CMS framework, which, via its "action on demand" mechanisms, allows the user to selectively load desired modules and to configure and tune the final application. The complete CMS detector is rather complex with more than 1 million geometrical volumes. OSCAR has been validated by comparing its results with test beam data and with results from simulation with a GEANT3-based program. It has been successfully deployed in the 2004 data challenge for CMS, where more than 35 million events for various LHC physics channels were simulated and analysed.
2004
Cited 7 times
Total cross-section, elastic scattering and diffraction dissociation at the Large Hadron Collider at CERN
DOI: 10.48550/arxiv.0903.3861
2009
Cited 5 times
Proceedings of the workshop: HERA and the LHC workshop series on the implications of HERA for LHC physics
2nd workshop on the implications of HERA for LHC physics. Working groups: Parton Density Functions Multi-jet final states and energy flows Heavy quarks (charm and beauty) Diffraction Cosmic Rays Monte Carlos and Tools
DOI: 10.1088/1742-6596/194/1/012001
2009
Cited 4 times
The structure behind it all
The talk discussed collisions where the structure of the systems involved plays a decisive role for the outcome of the event. For many types of charge changing processes the presence of resonant states can change the probability for a certain reaction by orders of magnitude. One example of this is electron-ion recombination where the resonant states are doubly or even multiply excited states lying above the ionization threshold of the recombined ion. The concept of a resonant state is discussed with the help of a simple model. The influence of such states is then illustrated through a few examples where some different calculational methods are compared with experiments. Finally, the possibility to also obtain accurate spectroscopical information from a collisional process is discussed.
DOI: 10.1103/physreva.80.052112
2009
Cited 3 times
Environmentally induced shift of the quantum arrival time
Using a simple model potential, we study the effects of weak Markovian dissipation on the quantum arrival time. The interaction with the environment is incorporated into the dynamics through a Markovian master equation of Lindblad type, which allows us to compare time-of-arrival distributions and approximate crossing probabilities for different dissipation strengths and temperatures. We also establish a connection to an earlier study where quantum tunneling with dissipation was investigated, which leads us to some conclusions concerning the formulation of the continuity equation in the Lindblad theory.
DOI: 10.48550/arxiv.1012.5169
2010
Cited 3 times
Forward Physics at the LHC (Elba 2010)
The papers review the main theoretical and experimental aspects of the Forward Physics at the Large Hadron Collider.
DOI: 10.1016/j.nima.2012.08.084
2013
Status of the TOTEM experiment at LHC
The TOTEM experiment is dedicated to the measurement of the total proton–proton cross-section with the luminosity-independent method and the study of elastic and diffractive scattering processes. Two tracking telescopes, T1 and T2, integrated in the CMS detector, cover the pseudo-rapidity region between 3.1 and 6.5 on both sides of the interaction point IP5. The Roman Pot (RP) stations are located at distances of ±147 m and ±220 m with respect to the interaction point to measure the very forward scattered protons at very small angles. During the LHC technical stop in winter 2010/2011, the TOTEM experiment was completed with the installation of the T1 telescope and the RP stations at ±147 m. In 2011, the LHC machine provided special optics with the large ß⁎=90 m, allowing TOTEM to measure the elastic scattering differential cross-section, down to the four-momentum transfer squared |t|=2×10−2 GeV2. Using the optical theorem and extrapolation of the differential cross-section to t=0 (optical point), the total p–p cross-section at the LHC energy of s=7TeV could be computed for the first time. Furthermore we measured with standard LHC beam optics and the energy of s=7TeV the forward charged particle pseudorapidity density dn/dη in the range of 5.3<|η|<6.4. The status of the experiment, the performance of the detectors with emphasis on the RPs are described and the first physics results are presented.
DOI: 10.1093/eurjcn/zvad064.112
2023
How patients affected by heart failure and other chronic conditions perform general and specific self-care behaviors
Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Centre of Excellence for Nursing Scholarship (CECRI), Rome, Italy. Background Older adults affected by chronic conditions (i.e., heart failure or any other chronic condition) need to perform self-care. It includes behaviors to maintain a healthy lifestyle (self-care maintenance), monitor signs and symptoms of chronic diseases (self-care monitoring), and manage them (self-care management). Performing self-care, allows patients to improve their quality of life, reduce hospital admission rates, and mortality. In patients affected by Heart Failure (HF) and other chronic conditions, also specific self-care behaviors are needed. To date, no prior studies have investigated general and specific self-care behaviors in patients with HF and other chronic conditions. Purpose Investigate how patients affected by HF and other chronic conditions perform general and specific self-care. Methods Cross-sectional study. We collected data from April 2017 to October 2021 in Italy. Patients with HF and other chronic conditions with more than 65 y/o were enrolled in community and outpatient settings. The Self-Care of Chronic Illness Inventory (SC-CII) and The Self-Care of Heart Failure Index (SCHFI) were used to measure generic and specific self-care behaviors, respectively. Values ≥70 indicate adequate self-care behaviors. Paired t-test was performed to identify differences between SC-CII and SCHFI scores. Results A sample of 369 patients with HF was enrolled. 53.3% was female with a mean age of 78.91(±7.41) years, and a median of 3 chronic conditions. The two chronic conditions most frequently associated with HF were Hypertension (75%) and Diabetes Mellitus (70%). Results showed inadequate general self-care maintenance (66.11±14.7) and management (57.77±20.1). Instead, general self-care monitoring was adequate (76.26±20.4). Specific HF self-care maintenance, monitoring and management were inadequate and equal to 57.54 (±17.24), 53.41 (±25.32) and 54.48 (±20.02), respectively. Specific self-care in HF is significantly lower than general self-care behaviors (p&amp;lt;0.001). Conclusion Patients showed more difficulties performing general self-care maintenance and management respect self-care monitoring. Regarding specific HF self-care, patients perform inadequate self-care behaviors in all dimensions. Knowing the lower self-care behaviors is important for clinicians to develop tailored interventions. In particular, patients with HF and other chronic conditions need to be supported in specific self-care behaviors.
DOI: 10.1093/eurjcn/zvad064.114
2023
Caregiver contributions to general and specific self-care of patients affected by heart failure and other chronic conditions
Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Centre of Excellence for Nursing Scholarship (CECRI), Rome, Italy. Background Older adults with HF and other chronic conditions often need the support of informal caregivers in performing self-care. Caregiver contribution (CC) to patient’s self-care includes a series of recommendations (or acts to replace) made to the patient to keep their own health conditions stable and manage signs and symptoms of their chronic conditions. CC to general and specific patient self-care represents help that improves patient clinical outcomes and maintains the stability of chronic conditions. To date, no studies have investigated general and specific caregiver contributions to the self-care of patients with Heart Failure (HF) and other chronic conditions. Purpose Investigate caregiver contribution to general and specific self-care in patients affected by HF and other chronic conditions. Methods Cross-sectional study. Data collection was conducted in community and outpatient settings, from April 2017 to October 2021. Caregivers of patients affected by HF and other chronic condition were enrolled if they were &amp;gt;18 years old and identified by the patient as the primary informal caregiver. Caregiver Contribution to Self-Care of Chronic Illness Inventory (CC-SC-CII) and Caregiver Contribution to Self-Care of Heart Failure Index (CC-SCHFI), were used for measuring generic and specific CC to self-care, respectively. Values ≥70 indicate adequate CC to general and specific self-care behaviors. Paired t-test was carried out to test differences in CC-SC-CII and CC-SCHFI scores. Results This study enrolled 369 caregivers caring for HF patients and other chronic conditions. The sample was composed mainly of females (61.27%) with a mean age of 45.0 (±1.41) years, and that lived with their loved ones (55.28%). The two chronic conditions most frequently associated in patients with HF cared for by informal caregivers were hypertension (75%) and diabetes mellitus (70%). General CC to self-care maintenance, monitoring, and management were adequate with mean scores of 70.57 (±21.6), 81.47 (±21.85), and 72.98 (±20.61), respectively. Specific CC to self-care maintenance, monitoring, and management were inadequate with mean scores of 64.49 (±16.76), 54.08 (±26.71), and 65.24 (±17.25), respectively. CC-SC-CII scores were significantly (p&amp;lt;.0001) higher than CC-SCHFI scores. Conclusion Caregivers showed more difficulties in the contribution to specific HF self-care compared to general self-care behaviors. Knowing how caregivers contribute to self-care is important for clinicians to develop psychosocial interventions for improving CC to self-care in patients with HF and other chronic conditions.
DOI: 10.1088/1748-0221/5/08/c08006
2010
Isotopic tuning of the 2<sup>3</sup><i>P</i><sub>0</sub>−2<sup>1</sup><i>S</i><sub>0</sub>and 2<sup>3</sup><i>P</i><sub>1</sub>−2<sup>1</sup><i>S</i><sub>0</sub>transition energies in He-like ions for future parity-nonconservation experiments
Crossings of opposite-parity levels in He-like ions for particular values of the atomic number Z offer excellent conditions for precise experimental tests of parity-nonconservation (PNC). Such tests may be performed by inducing, through intense lasers, transitions that are only allowed in presence of PNC. Several spectroscopy experiments have been proposed in the past, but only now, with the advent of high-intensity laser facilities (e.g. PHELIX at GSI or POLARIS at Jena), their feasibility is within reach. In this paper, we use relativistic many-body perturbation theory (RMBPT) to calculate accurately the crossing conditions of the excited levels (1s2s) 1S0 and (1s2p) 3P0 and of (1s2s) 1S0 and (1s2p) 3P1 in intermediate and heavy He-like ions. Moreover, we show the dependence of the energy splittings upon the choice of the nuclear isotope.
DOI: 10.1140/epjb/e2006-00101-6
2006
Cited 3 times
Nonextensive interpretation of radiative recombination in electron cooling
An interest for the low-energy range of the nonextensive distribution function arises from the study of radiative recombination in electron cooling devices in particle accelerators, whose experimentally measured reaction rates are much above the theoretical prediction. The use of generalized distributions, that differ from the Maxwellian in the low energy part (due to subdiffusion between electron and ion bunches), may account for the observed rate enhancement. In this work, we consider the isotropic distribution function and we propose a possible experiment for verifying the existence of a cut-off in the generalized momentum distribution, by measuring the spectrum of the X-rays emitted from radiative recombination reactions.
DOI: 10.1109/pac.2005.1590883
2006
Cited 3 times
Tests of A Roman Pot Prototype for the Totem Experiment
The TOTEM collaboration has developed and tested the first prototype of its Roman Pots to be operated in the LHC. TOTEM Roman Pots contain stacks of silicon detectors with strips oriented in two orthogonal directions. To measure proton scattering angles of a few microradians, the detectors will approach the beam centre to a distance of 10σ + 0.5 mm (= 1.3 mm). Dead space near the detector edge is minimised by using two novel "edgeless" detector technologies. The silicon detectors are used both for precise track reconstruction and for triggering. The first full-sized prototypes of both detector technologies as well as their read-out electronics have been developed, built and operated. The tests took place in the proton beam-line of the SPS accelerator ring. In addition, the pot's shielding against electromagnetic interference and the longitudinal beam coupling impedance have been measured with the wire method.
DOI: 10.1109/nssmic.2004.1462231
2005
Cited 3 times
Design and construction of the triple GEM detector for TOTEM
We describe the design and construction of the first triple-GEM chamber prototypes for the TOTEM detector at CERN LHC. The chambers are semicircular, with an inner and outer radius of the active area of about 40 and 150 mm; six to eight detectors will be mounted on each arm. Each chamber has analogue readout of the charge on concentric circular strips, at 400 /spl mu/m pitch, to obtain the radial coordinates, and about 1000 pads of sizes between 3/spl times/3 and 7/spl times/7 mm/sup 2/ with digital readout, used to generate the triggering in combination with the other chambers.
2004
Cited 3 times
Total cross-section, elastic scattering and diffraction dissociation at the Large Hadron Collider at CERN : TOTEM Technical Design Report
DOI: 10.1393/ncb/i2008-10528-4
2008
Luminosity measurements at LHC
DOI: 10.1139/p10-069
2011
Hyperfine interaction effects on the (1s2p)<sup>3</sup>P<sub>1</sub>–(1s2s)<sup>1</sup>S<sub>0</sub> energy splitting in He-like ions for parity nonconservation studiesThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.
Accurate theoretical knowledge of the (1s2p) 3 P 1 –(1s2s) 1 S 0 splitting in He-like ions is demanded for future experimental studies of the nuclear spin-dependent part of the weak interaction. In this paper we perform a calculation of the hyperfine structure of (1s2p) 3 P 1 –(1s2s) 1 S 0 within 3 ≤ Z ≤ 35, Z being the atomic number. In this Z range parity nonconservation (PNC) effects are amplified by the close energy proximity of the opposite parity levels (1s2p) 3 P 1 and (1s2s) 1 S 0 . We find that the hyperfine structure is relevant for Z &gt; 12, and produces splitting among the hyperfine sublevels as large as 150 meV for medium Z He-like ions (Z ∼ 35).
DOI: 10.1016/j.nima.2012.10.124
2013
The electronics system of the TOTEM T1 telescope
The T1 detector of the TOTEM experiment is devoted to the measurement of the inelastic rate of proton–proton interactions at the LHC. It is made of Cathode Strip Chambers. The complete electronic chains of front-end, readout and trigger are presented here. The electronics system has been developed keeping into account the hostile environment from the point of view of both radiation and magnetic field. Dedicated VLSI circuits have been extensively used in order to optimize space and power consumption.
2013
Summary of the Workshop on Multi-Parton Interactions (MPI@LHC 2012)
With short resumes and highlights the discussions in the different working groups of the workshop MPI@LHC 2012 is documented.
DOI: 10.1088/1748-0221/10/08/c08002
2015
Laboratory and testbeam results for thin and epitaxial planar sensors for HL-LHC
The High-Luminosity LHC (HL-LHC) upgrade of the CMS pixel detector will require the development of novel pixel sensors which can withstand the increase in instantaneous luminosity to L=5×1034 cm−2s−1 and collect ∼ 3000 fb−1 of data. The innermost layer of the pixel detector will be exposed to doses of about 1016 neq/ cm2. Hence, new pixel sensors with improved radiation hardness need to be investigated. A variety of silicon materials (Float-zone, Magnetic Czochralski and Epitaxially grown silicon), with thicknesses from 50 μm to 320 μm in p-type and n-type substrates have been fabricated using single-sided processing. The effect of reducing the sensor active thickness to improve radiation hardness by using various techniques (deep diffusion, wafer thinning, or growing epitaxial silicon on a handle wafer) has been studied. The results for electrical characterization, charge collection efficiency, and position resolution of various n-on-p pixel sensors with different substrates and different pixel geometries (different bias dot gaps and pixel implant sizes) will be presented.
DOI: 10.1109/nssmic.2011.6154341
2011
The TOTEM experiment at LHC
The TOTEM experiment is dedicated to the measurement of the total proton-proton cross-section with the luminosity-independent method and the study of elastic and diffractive scattering processes. Two tracking telescopes, T1 and T2, integrated in the CMS detector, cover the pseudo-rapidity region between 3.1 and 6.5 on both sides of the interaction point IP5. The Roman Pot (RP) stations are located at distances of ± 147m and ± 220 m with respect to the interaction point to measure the very forward scattered protons at very small angles. During the LHC technical stop in winter 2010/2011, the TOTEM experiment was completed with the installation of the T1 telescope and the RP stations at ± 147 m. In 2011, the LHC machine provided special optics with the large ß* = 90 m, allowing TOTEM to measure the elastic scattering differential cross section, down to the four-momentum transfer squared |t| = 2×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> GeV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Using the optical theorem and extrapolation of the differential cross section to t = 0 (optical point), the total p-p cross section at the LHC energy of √v = 7 TeV could be computed for the first time. The status of the experiment, the performance of the detectors with emphasis on the RPs are described and the first physics results are presented.
DOI: 10.48550/arxiv.1411.4963
2014
Measurement of the forward charged particle pseudorapidity density in pp collisions at sqrt(s) = 8 TeV using a displaced interaction point
The pseudorapidity density of charged particles dN(ch)/deta is measured by the TOTEM experiment in pp collisions at sqrt(s) = 8 TeV within the range 3.9 &lt; eta &lt; 4.7 and -6.95 &lt; eta &lt; -6.9. Data were collected in a low intensity LHC run with collisions occurring at a distance of 11.25 m from the nominal interaction point. The data sample is expected to include 96-97\% of the inelastic proton-proton interactions. The measurement reported here considers charged particles with p_T &gt; 0 MeV/c, produced in inelastic interactions with at least one charged particle in -7 &lt; eta &lt; -6 or 3.7 &lt; eta &lt;4.8 . The dN(ch)/deta has been found to decrease with |eta|, from 5.11 +- 0.73 at eta = 3.95 to 1.81 +- 0.56 at eta= - 6.925. Several MC generators are compared to the data and are found to be within the systematic uncertainty of the measurement.
DOI: 10.48550/arxiv.1204.5689
2012
Elastic Scattering and Total Cross-Section in p+p reactions measured by the LHC Experiment TOTEM at sqrt(s) = 7 TeV
Proton-proton elastic scattering has been measured by the TOTEM experiment at the CERN Large Hadron Collider at $\sqrt{s} = 7 $ TeV in special runs with the Roman Pot detectors placed as close to the outgoing beam as seven times the transverse beam size. The differential cross-section measurements are reported in the |t|-range of 0.36 to 2.5 GeV^2. Extending the range of data to low t values from 0.02 to 0.33 GeV^2,and utilizing the luminosity measurements of CMS, the total proton-proton cross section at sqrt(s) = 7 TeV is measured to be (98.3 +- 0.2(stat) +- 2.8(syst)) mb.
2009
TOTEM early measurements
2006
New detectors for the kaon and hypernuclear experiments with KaoS at MAMI and with PANDA at GSI
The KaoS spectrometer at the Mainz Microtron MAMI, Germany, is perceived as the ideal candidate for a dedicated spectrometer in kaon and hypernuclei electroproduction. KaoS will be equipped with new read-out electronics, a completely new focal plane detector package consisting of scintillating fibres, and a new trigger system. First prototypes of the fibre detectors and the associated new front-end electronics are shown in this contribution. The Mainz hypernuclei research program will complement the hypernuclear experiments at the planned FAIR facility at GSI, Germany. At the proposed antiproton storage ring the spectroscopy of double Lambda hypernuclei is one of the four main topics which will be addressed by the PANDA Collaboration. The experiments require the operation of high purity germanium (HPGe) detectors in high magnetic fields (B= 1T) in the presence of a large hadronic background. The performance of high resolution Ge detectors in such an environment has been investigated
DOI: 10.1109/nssmic.2006.354216
2006
The CMS Simulation Software
In this paper we present the features and the expected performance of the re-designed CMS simulation software, as well as the experience from the migration process. Today, the CMS simulation suite is based on the two principal components - Geant4 detector simulation toolkit and the new CMS offline Framework and Event Data Model. The simulation chain includes event generation, detector simulation, and digitization steps. With Geant4, we employ the full set of electromagnetic and hadronic physics processes and detailed particle tracking in the 4 Tesla magnetic field. The Framework provides "action on demand" mechanisms, to allow users to load dynamically the desired modules and to configure and tune the final application at the run time. The simulation suite is used to model the complete central CMS detector (over 1 million of geometrical volumes) and the forward systems, such as Castor calorimeter and Zero Degree Calorimeter, the Totem telescopes, Roman Pots, and the Luminosity Monitor. The designs also previews the use of the electromagnetic and hadronic showers parametrization, instead of full modelling of high energy particles passage through a complex hierarchy of volumes and materials, allowing significant gain in speed while tuning the simulation to test beam and collider data. Physics simulation has been extensively validated by comparison with test beam data and previous simulation results. The redesigned and upgraded simulation software was exercised for performance and robustness tests. It went into Production in July 2006, running in the US and EU grids, and has since delivered about 60 millions of events.
2006
Triggering on forward physics
DOI: 10.1393/ncr/i2014-10101-y
2014
High-energy proton cross sections
The measurements of the total, elastic and diffractive proton-proton cross sections at high energies are shown. The article mainly focuses on the recent results of the experiments at the Large Hadron Collider and on the methods and techniques used to perform the measurements. The general properties of the scattering amplitude are also presented, together with the main aspects of some of the most successful theoretical models, whose predictions are compared with the experimental results.
2011
First Results from the TOTEM Experiment
The first physics results from the TOTEM experiment are here reported, concerning the measurements of the total, differential elastic, elastic and inelastic pp cross-section at the LHC energy of $\sqrt{s}$ = 7 TeV, obtained using the luminosity measurement from CMS. A preliminary measurement of the forward charged particle $\eta$ distribution is also shown.
2011
Elastic pp Scattering at the LHC at √ s =7 TeV.
2012
TOTEM status and results
2011
First TOTEM measurement of large |t| proton proton elastic scattering at the LHC energy of s**(1/2) = 7-TeV
DOI: 10.48550/arxiv.1110.1008
2011
First Results from the TOTEM Experiment
The first physics results from the TOTEM experiment are here reported, concerning the measurements of the total, differential elastic, elastic and inelastic pp cross-section at the LHC energy of $\sqrt{s}$ = 7 TeV, obtained using the luminosity measurement from CMS. A preliminary measurement of the forward charged particle $η$ distribution is also shown.
2012
Elastic Scattering and Total Cross-Section in p+p Reactions : As Measured by the LHC Experiment TOTEM at √ =7 TeV(Forward and Diffraction Physics and Cosmic Rays,Multiparticle Dynamics)
2010
Forward Physics at the LHC (Elba 2010)
The papers review the main theoretical and experimental aspects of the Forward Physics at the Large Hadron Collider.
DOI: 10.22323/1.102.0023
2010
Diffraction, total cross section, forward physics LHC
DOI: 10.1142/9789814307529_0108
2010
Offline Software for the TOTEM Experiment at the LHC
V. Avati , M. Berretti, M. Besta, E. Brucken, P. Dadel, F. Ferro, F. Garcia, S. Giani, L. Grzanka, J. Hallila, P. Janhunen , J. Kaspar, G. Latino, R. Leszko, D. Mierzejewski, H. Niewiadomski, T. Novak, T. Nuotio, E. Oliveri, K. Osterberg, F. Oljemark, S. Sadilov, M. Tuhkanen , T. Vihanta, M. Zalewski, Z. Zhang, J. Welti Case Western Reserve University, Dept. of Physics, Cleveland, OH, USA CERN, Geneve, Switzerland Helsinki Institute of Physics and Dept. of Physics, University of Helsinki,Finland Institute of Physics of the Academy of Sciences, Praha, Czech Republic MTA KFKI RMKI, Budapest, Hungary INFN Sezione di Genova, Italy Universita di Siena and INFN Sezione di Pisa, Italy On leave from AGH Univ. of Sci. and Technology, Krakow, Poland On leave from University of Applied Sciences, Rovaniemi, Finland ∗Corresponding Author E-mail: valentina.avati@cern.ch
2010
Diffraction at TOTEM
DOI: 10.1063/1.4977149
2017
CT-PPS: The program and its possible development
The CMS-TOTEM Precision Proton Spectrometer (CT-PPS) has the goal of studying central exclusive production processes in proton-proton collisions at LHC. Such processes are characterized by the presence of two protons scattered at small angles and detected inside the LHC beam pipe with CT-PPS, along with one or more particles produced at small rapidity values and detected by the central CMS detector. This provides access to a variety of interesting subjects, including the study of quartic gauge couplings and searches for new resonances produced in photon-photon or gluon-gluon fusion. A description of the experimental set-up is presented, along with the current status of the project.
DOI: 10.1088/1742-6596/934/1/012025
2017
Measurements, status and plans of the TOTEM experiment at the LHC
The TOTEM collaboration at the LHC has measured the elastic, inelastic and total proton-proton cross sections at several center of mass energies and is carrying on a rich program of measurements of diffractive physics together with the CMS collaboration. The talk will review the TOTEM measurements mainly focusing on the newest and most significant ones. The status of the experimental apparatus, its latest changes and the current and future technological challenges will be discussed as well.
DOI: 10.22323/1.028.0167
2010
Dielectronic recombination rates in astrophysical plasmas
In this work we introduce a new expression of the plasma Dielecronic Recombination (DR) rate as a function of the temperature, derived assuming a small deformation of the Maxwell-Boltzmann distribution and containing corrective factors, in addition to the usual exponential behaviour, caused by non-linear effects in slightly non ideal plasmas.We then compare the calculated DR rates with the experimental DR fits in the low temperature region.
DOI: 10.22323/1.028.0094
2010
Microdynamical effects on momentum distribution in stellar plasmas
We show that, if a random force is present, the microscopic dynamics of ion elastic collisions and quantum effects may sensibly modify the momentum distribution of ions and electrons in stellar plasmas.We also show that a few microscopic interactions among the particles, that are significant in very specific energy intervals, lead to peculiar slight corrections to the usual Maxwell-Boltzmann distribution.All these modifications can be easily taken into account by using the nonextensive statistical mechanics.Consequences on the resonant and non-resonant fusion rates are remarkable and may affect strongly some astrophysical processes.A few examples are reported.
2009
Elastic scattering, diffraction and forward physics at the LHC
The 6 LHC experiments are equipped with detectors placed in the forward regions of the 4 interaction points. The first part of this article reviews the s tatus of these detectors in the very moment the first proton-proton collisions take place. The se cond part is dedicated to review the main forward physics processes at the LHC and how they can be measured by the experimental apparatus.
DOI: 10.1088/1742-6596/194/6/062019
2009
Relativistic Many-Body Perturbation Theory approach to electron-ion recombination of He- and Be-like systems
We report on efforts to perform fully correlated calculations of effective three-body systems with a Rel-ativistic Many-Body Perturbation Theory approach. A preliminary version of the program is used on resonances in Ge27+, formed in collisions of electrons with Be-like Ge28+. We will show a comparison between experimental and calculated spectra, including both dielectronic and trielectronic recombination resonances. Results for some pure three electron systems will also be shown.
DOI: 10.1016/j.nuclphysbps.2007.11.107
2008
Diffraction: prospects for the LHC
The combination of CMS and TOTEM provides an unprecedented coverage in pseudo-rapidity at a hadron collider. Both collaborations intend to carry out a joint diffractive and forward physics program. This program includes studying fundamental aspects of soft QCD via inclusive single-diffraction and inclusive double-Pomeron exchange, as well as studying diffraction in the presence of a hard scale and using central exclusive production as a tool for discovery physics. Also possible is a rich program on low-x physics where Bjorken x values as low as 10−6 to 10−7 are within reach.
2009
Charge-state Selected Detection of Photons from Electron-Ion Interactions in an EBIT
This thesis contains experimental work that was performed at two state-of-the art devices for electron-ion collision physics, at a heavy-ion storage ring and at an Electron Beam Ion Trap. As a result, absolute recombination rate coefficients for H-like Si, He-like Si, Be-like Si, and Na-like Si, as well as Be-like Ne, Na-like S and Na-like Ar are reported over a wide energy range from μeV to keV. The experimentally derived recombination spectra are compared with results of Many Body Perturbation Theory calculations and AUTOSTRUCTURE calculations. Furthermore, the effect of external electric fields on the recombination rate is investigated for two Na-like ions, and a strong enhancement of dielectronic recombination into high Rydberg states is observed. Experimental plasma rate coefficients are derived for the studied ions for the first time and are compared with calculated values available in the literature. In the EBIT experiment, a novel extraction method provides complete charge state spectra of the ions for every extraction. Absolute DR rate coefficients for both H-like Si and He-like Si are obtained from the same measurement. Comparison with recorded X-ray spectra enables the separation of the photon spectra arising from charge-changing and charge-preserving reactions and facilitates the extraction of electron impact excitation rate coefficients.
2009
3rd Workshop on the Implications of HERA for LHC Physics
DOI: 10.3204/desy-proc-2009-02/20
2008
Diffraction at TOTEM
2008
Technical Note Resolution, efficiency and stability of HPGe detector operating in a magnetic field at various gamma-ray energies
The use of High Purity Germanium detectors (HPGe) has been planned in some future experiments of hadronic physics. The crystals will be located close to large spectrometers where the magnetic fringing field will not be negligible and their performances might change. Moreover high precision is required in these experiments. The contribution of magnetic field presence and long term measurements is unique. In this paper the results of systematic measurements of the resolution, stability and efficiency of a crystal operating inside a magnetic field of 0.8 T, using radioactive sources in the energy range from 0.08 to 1.33 MeV, are reported. The measurements have been repeated during several months in order to test if any permanent damage occurred. The resolution at 1.117 and 1.332 MeV gamma-rays from a 60 Co source has been measured at different magnetic fields in the range of 0–0.8 T and the results are compared with the previous
2008
Diffraction at TOTEM
The TOTEM experiment at the LHC measures the total proton-proton cross section with the luminosity-independent method and the elastic proton-proton cross-section over a wide |t|-range. It also performs a comprehensive study of diffraction, spanning from cross-section measurements of individual diffractive processes to the analysis of their event topologies. Hard diffraction will be studied in collaboration with CMS taking advantage of the large common rapidity coverage for charged and neutral particle detection and the large variety of trigger possibilities even at large luminosities. TOTEM will take data under all LHC beam conditions including standard high luminosity runs to maximize its physics reach. This contribution describes the main features of the TOTEM physics programme including measurements to be made in the early LHC runs. In addition, a novel scheme to extend the diffractive proton acceptance for high luminosity runs by installing proton detectors at IP3 is described.
2009
Diffraction, total cross section, forward physics LHC
DOI: 10.21468/scipostphysproc.8.062
2022
Proton reconstruction with the Precision Proton Spectrometer (PPS) in Run 2 and the PPS at HL-LHC
The Precision Proton Spectrometer (PPS) started operating in 2016 and has collected more than 110 fb ^{-1} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi /><mml:mrow><mml:mo>−</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math> of data over the course of the LHC Run 2, now fully available for physics analysis. This contribution covers the key features of the PPS alignment and optics calibration, which have been developed from scratch. The reconstructed proton distributions, the performance of the PPS simulation and finally the validation of the full reconstruction chain with physics data (dilepton events) are also illustrated.