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Michał Szleper

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DOI: 10.1016/s0550-3213(96)00538-x
1997
Cited 349 times
Measurement of the proton and deuteron structure functions, F2 and F2, and of the ratio
The muon-proton and muon-deuteron inclusive deep inelastic scattering cross sections were measured in the kinematic range 0.002 < × < 0.60 and 0.5 < Q2 < 75 GeV2 at incident muon energies of 90, 120, 200 and 280 GeV. These results are based on the full data set collected by the New Muon Collaboration, including the data taken with a small angle trigger. The extracted values of the structure functions F2p and F2d are in good agreement with those from other experiments. The data cover a sufficient range of y to allow the determination of the ratio of the longitudinally to transversely polarised virtual photon absorption cross sections, R = σLσT, for 0.002 < × < 0.12. The values of R are compatible with a perturbative QCD prediction; they agree with earlier measurements and extend to smaller x.
DOI: 10.1016/j.physrep.2005.12.003
2006
Cited 313 times
Physics interplay of the LHC and the ILC
Physics at the Large Hadron Collider (LHC) and the International e+e- Linear Collider (ILC) will be complementary in many respects, as has been demonstrated at previous generations of hadron and lepton colliders. This report addresses the possible interplay between the LHC and ILC in testing the Standard Model and in discovering and determining the origin of new physics. Mutual benefits for the physics programme at both machines can occur both at the level of a combined interpretation of Hadron Collider and Linear Collider data and at the level of combined analyses of the data, where results obtained at one machine can directly influence the way analyses are carried out at the other machine. Topics under study comprise the physics of weak and strong electroweak symmetry breaking, supersymmetric models, new gauge theories, models with extra dimensions, and electroweak and QCD precision physics. The status of the work that has been carried out within the LHC/ILC Study Group so far is summarized in this report. Possible topics for future studies are outlined.
DOI: 10.1016/j.physletb.2015.04.068
2015
Cited 236 times
Search for the dark photon in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mrow><mml:mi>π</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:math>decays
A sample of 1.69×107 fully reconstructed π0→γe+e− decay candidates collected by the NA48/2 experiment at CERN in 2003–2004 is analyzed to search for the dark photon (A′) production in the π0→γA′ decay followed by the prompt A′→e+e− decay. No signal is observed, and an exclusion region in the plane of the dark photon mass mA′ and mixing parameter ε2 is established. The obtained upper limits on ε2 are more stringent than the previous limits in the mass range 9MeV/c2<mA′<70MeV/c2. The NA48/2 sensitivity to the dark photon production in the K±→π±A′ decay is also evaluated.
DOI: 10.1103/physrevd.50.r1
1994
Cited 289 times
Reevaluation of the Gottfried sum
We present a new determination of the nonsinglet structure function ${\mathit{F}}_{2}^{\mathit{p}}$ - ${\mathit{F}}_{2}^{\mathit{n}}$ at ${\mathit{Q}}^{2}$=4 ${\mathrm{GeV}}^{2}$ using recently measured values of ${\mathit{F}}_{2}^{\mathit{d}}$ and ${\mathit{F}}_{2}^{\mathit{n}}$/${\mathit{F}}_{2}^{\mathit{p}}$. A new evaluation of the Gottfried sum is given, which remains below the simple quark-parton model value of 1/3.
DOI: 10.1016/0370-2693(95)01318-9
1995
Cited 209 times
Measurement of the proton and the deuteron structure functions, F2 and F2
The proton and deuteron structure funtions F2p and F2d were measured in the kinematic range 0.006 < x < 0.6 and 0.5 < Q2 < 75 GeV2, by inclusive deep inelastic muon scattering at 90, 120, 200 and 280 GeV. The measurements are in good agreement with earlier high precision results. The present and earlier results together have been parametrised to give descriptions of the proton and deuteron structure functions F2 and their uncertainties over the range 0.006 < x < 0.9.
DOI: 10.1016/0550-3213(95)00023-2
1995
Cited 143 times
The structure function ratios F2C/F2D and F2C/F2D at small x
We present the structure function ratios measured in deep inelastic muonnucleus scattering at a nominal incident muon energy of 200 GeV The kinematic range is covered. For values of x less than 0.002 both ratios indicate saturation of shadowing at values compatible with photoabsorption results.
DOI: 10.1016/s0550-3213(96)00673-6
1997
Cited 123 times
Accurate measurement of F2d/F2p and Rd − Rp
Results are presented for F2d/F2p and Rd − Rp from simultaneous measurements of deep inelastic muon scattering on hydrogen and deuterium targets, at 90, 120, 200 and 280 GeV. The difference Rd − Rp, determined in the range 0.002 < x < 0.4 at an average Q2 of 5 GeV2, is compatible with zero. The x and Q2 dependence of F2d/F2p was measured in the kinematic range 0.001 < x < 0.8 and 0.1 < Q2 < 145 GeV2 with small statistical and systematic errors. For x > 0.1 the ratio decreases with Q2.
DOI: 10.1016/j.physletb.2005.11.087
2006
Cited 119 times
Observation of a cusp-like structure in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math> invariant mass distribution from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"><mml:msup><mml:mi>K</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo…
We report the results from a study of a partial sample of ∼2.3×107 K±→π±π0π0 decays recorded by the NA48/2 experiment at the CERN SPS, showing an anomaly in the π0π0 invariant mass (M00) distribution in the region around M00=2m+, where m+ is the charged pion mass. This anomaly, never observed in previous experiments, can be interpreted as an effect due mainly to the final state charge exchange scattering process π+π−→π0π0 in K±→π±π+π− decay [N. Cabibbo, Phys. Rev. Lett. 93 (2004) 121801]. It provides a precise determination of a0−a2, the difference between the ππ scattering lengths in the isospin I=0 and I=2 states. A best fit to a rescattering model [N. Cabibbo, G. Isidori, JHEP 0503 (2005) 21] corrected for isospin symmetry breaking gives (a0−a2)m+=0.268±0.010(stat)±0.004(syst), with additional external uncertainties of ±0.013 from branching ratio and theoretical uncertainties. If the correlation between a0 and a2 predicted by chiral symmetry is taken into account, this result becomes (a0−a2)m+=0.264±0.006(stat)±0.004(syst)±0.013(ext).
DOI: 10.1140/epjc/s10052-010-1480-6
2010
Cited 101 times
Precise tests of low energy QCD from $\mbox {$\mathrm {K}_{\mathrm {e}4}$}$ decay properties
We report results from the analysis of the $\mbox {$\mathrm {K}^{\pm}$}\rightarrow \pi^{+} \pi^{-} \mathrm{e}^{\pm} \nu$ ( $\mbox {$\mathrm {K}_{\mathrm {e}4}$}$ ) decay by the NA48/2 collaboration at the CERN SPS, based on the total statistics of 1.13 million decays collected in 2003–2004. The hadronic form factors in the S- and P-wave and their variation with energy are obtained. The phase difference between the S- and P-wave states of the ππ system is accurately measured and allows a precise determination of $\mbox {$a_{0}^{0}$}$ and $\mbox {$a_{0}^{2}$}$ , the I = 0 and I = 2 S-wave ππ scattering lengths: $\mbox {$a_{0}^{0}$}= 0.2220 \pm 0.0128 \mbox {$\mathrm {_{stat}}$}\pm 0.0050 \mbox {$\mathrm {_{syst}}$}\pm 0.0037\mbox {$\mathrm {_{th}}$},\mbox {$a_{0}^{2}$}= -0.0432 \pm 0.0086 \mbox {$\mathrm {_{stat}}$}\pm 0.0034 \mbox {$\mathrm {_{syst}}$}\pm 0.0028\mbox {$\mathrm {_{th}}$}$ . Combination of this result with the other NA48/2 measurement obtained in the study of $\mbox {$\mbox {$\mathrm {K}^{\pm}$}\rightarrow \mbox {$\pi ^{0}$}\mbox {$\pi ^{0}$}\mbox {$\scriptstyle \pi ^{\pm }$}$}$ decays brings an improved determination of $\mbox {$a_{0}^{0}$}$ and the first precise experimental measurement of $\mbox {$a_{0}^{2}$}$ , providing a stringent test of Chiral Perturbation Theory predictions and lattice QCD calculations. Using constraints based on analyticity and chiral symmetry, even more precise values are obtained: $\mbox {$a_{0}^{0}$}=0.2196 \pm 0.0028\mbox {$\mathrm {_{stat}}$}\pm 0.0020 \mbox {$\mathrm {_{syst}}$}$ and $\mbox {$a_{0}^{2}$}= -0.0444 \pm 0.0007 \mbox {$\mathrm {_{stat}}$}\pm 0.0005 \mbox {$\mathrm {_{syst}}$}\pm 0.0008 \mbox {$\mathrm {_{ChPT}}$}$ .
DOI: 10.1140/epjc/s10052-008-0547-0
2008
Cited 99 times
New high statistics measurement of Ke4 decay form factors and ππ scattering phase shifts
We report results from a new measurement of the Ke4 decay K±→π+π-e±ν by the NA48/2 collaboration at the CERN SPS, based on a partial sample of more than 670 000 Ke4 decays in both charged modes collected in 2003. The form factors of the hadronic current (F,G,H) and ππ phase difference (δ=δs-δp) have been measured in ten independent bins of the ππ mass spectrum to investigate their variation. A sizeable acceptance at large ππ mass, a low background and a very good resolution contribute to an improved experimental accuracy, a factor two better than in the previous measurement, when extracting the ππ scattering lengths a0 0 and a0 2. Under the assumption of isospin symmetry and using numerical solutions of the Roy equations, the following values are obtained in the plane (a0 0,a0 2): a0 0=0.233±0.016stat±0.007syst,a0 2=-0.0471±0.011stat±0.004syst. The presence of potentially large isospin effects is also considered and will allow comparison with precise predictions from Chiral Perturbation Theory.
DOI: 10.48550/arxiv.1902.00134
2019
Cited 49 times
Higgs Physics at the HL-LHC and HE-LHC
The discovery of the Higgs boson in 2012, by the ATLAS and CMS experiments, was a success achieved with only a percent of the entire dataset foreseen for the LHC. It opened a landscape of possibilities in the study of Higgs boson properties, Electroweak Symmetry breaking and the Standard Model in general, as well as new avenues in probing new physics beyond the Standard Model. Six years after the discovery, with a conspicuously larger dataset collected during LHC Run 2 at a 13 TeV centre-of-mass energy, the theory and experimental particle physics communities have started a meticulous exploration of the potential for precision measurements of its properties. This includes studies of Higgs boson production and decays processes, the search for rare decays and production modes, high energy observables, and searches for an extended electroweak symmetry breaking sector. This report summarises the potential reach and opportunities in Higgs physics during the High Luminosity phase of the LHC, with an expected dataset of pp collisions at 14 TeV, corresponding to an integrated luminosity of 3 ab$^{-1}$. These studies are performed in light of the most recent analyses from LHC collaborations and the latest theoretical developments. The potential of an LHC upgrade, colliding protons at a centre-of-mass energy of 27 TeV and producing a dataset corresponding to an integrated luminosity of 15 ab$^{-1}$, is also discussed.
DOI: 10.1140/epjc/s10052-007-0456-7
2007
Cited 89 times
Search for direct CP violating charge asymmetries in K±→π±π+π- and K±→π±π0π0 decays
A measurement of the direct CP violating charge asymmetries of the Dalitz plot linear slopes Ag=(g+-g-)/(g++g-) in K±→π±π+π- and K±→π±π0π0 decays by the NA48/2 experiment at CERN SPS is presented. A new technique of asymmetry measurement involving simultaneous K+ and K- beams and a large data sample collected allowed a result of an unprecedented precision. The charge asymmetries were measured to be Ac g=(-1.5±2.2)×10-4 with 3.11×109K±→π±π+π- decays, and An g=(1.8±1.8)×10-4 with 9.13×107K±→π±π0π0 decays. The precision of the results is limited mainly by the size of the data sample.
DOI: 10.1016/0550-3213(94)90152-x
1994
Cited 89 times
Exclusive ϱ0 and φ muoproduction at large Q2
Exclusive ϱ0 and φ muoproduction on deuterium, carbon and calcium has been studied in the kinematic range 2< Q2< 25 GeV2 and 40 < ν < 180GeV. We discuss the Q2 dependence of the cross sections, the transverse momentum distributions for the vector mesons, the decay angular distributions and, in the case of the ϱ0, nuclear effects. The data for 0 production are compatible with a diffractive mechanism. The distinct features of φ production are a smaller cross section and less steep pt2 distributions than those for the 0 mesons.
DOI: 10.1140/epjc/s10052-009-1171-3
2009
Cited 66 times
Determination of the S-wave π π scattering lengths from a study of K ±→π ± π 0 π 0 decays
We report the results from a study of the full sample of ∼6.031×107 K ±→π ± π 0 π 0 decays recorded by the NA48/2 experiment at the CERN SPS. As first observed in this experiment, the π 0 π 0 invariant mass (M 00) distribution shows a cusp-like anomaly in the region around M 00=2m +, where m + is the charged pion mass. This anomaly has been interpreted as an effect due mainly to the final state charge exchange scattering process π + π −→π 0 π 0 in K ±→π ± π + π − decay. Fits to the M 00 distribution using two different theoretical formulations provide the presently most precise determination of a 0−a 2, the difference between the π π S-wave scattering lengths in the isospin I=0 and I=2 states. Higher-order π π rescattering terms, included in the two formulations, allow also an independent, though less precise, determination of a 2.
DOI: 10.1016/j.physletb.2011.01.042
2011
Cited 61 times
New measurement of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>K</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:msup><mml:mi>μ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>μ</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math> decay
A sample of 3120 K±→π±μ+μ− decay candidates with (3.3±0.7)% background contamination has been collected by the NA48/2 experiment at the CERN SPS, allowing a detailed study of the decay properties. The branching ratio was measured to be BR=(9.62±0.25)×10−8. The form factor W(z), where z=(Mμμ/MK)2, was parameterized according to several models. In particular, the slope of the linear form factor W(z)=W0(1+δz) was measured to be δ=3.11±0.57. Upper limits of 2.9×10−2 and 2.3×10−2 on possible charge asymmetry and forward–backward asymmetry were established at 90% CL. An upper limit BR(K±→π∓μ±μ±)<1.1×10−9 was established at 90% CL for the rate of the lepton number violating decay.
DOI: 10.1016/j.physletb.2009.05.040
2009
Cited 59 times
Precise measurement of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>K</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math> decay
A sample of 7253 $K^\pm\toπ^\pm e^+e^-(γ)$ decay candidates with 1.0% background contamination has been collected by the NA48/2 experiment at the CERN SPS, allowing a precise measurement of the decay properties. The branching ratio in the full kinematic range was measured to be ${\rm BR}=(3.11\pm0.12)\times 10^{-7}$, where the uncertainty includes also the model dependence. The shape of the form factor $W(z)$, where $z=(M_{ee}/M_K)^2$, was parameterized according to several models, and, in particular, the slope $δ$ of the linear form factor $W(z)=W_0(1+δz)$ was determined to be $δ=2.32\pm0.18$. A possible CP violating asymmetry of $K^+$ and $K^-$ decay widths was investigated, and a conservative upper limit of $2.1\times 10^{-2}$ at 90% CL was established.
DOI: 10.1140/epjc/s10052-018-5885-y
2018
Cited 31 times
Same-sign WW scattering at the LHC: can we discover BSM effects before discovering new states?
It is possible that measurements of vector boson scattering (VBS) at the LHC will reveal disagreement with Standard Model predictions, but no new particles will be observed directly. The task is then to learn as much as possible about the new physics from a VBS analysis carried within the framework of the Effective Field Theory (EFT). In this paper we discuss issues related to the correct usage of the EFT when the WW invariant mass is not directly accessible experimentally, as in purely leptonic W decay channels. The strategies for future data analyses in case such scenario indeed occurs are proposed.
DOI: 10.1016/j.revip.2022.100071
2022
Cited 11 times
Vector boson scattering processes: Status and prospects
Insight into the electroweak (EW) and Higgs sectors can be achieved through measurements of vector boson scattering (VBS) processes. The scattering of EW bosons are rare processes that are precisely predicted in the Standard Model (SM) and are closely related to the Higgs mechanism. Modifications to VBS processes are also predicted in models of physics beyond the SM (BSM), for example through changes to the Higgs boson couplings to gauge bosons and the resonant production of new particles. In this review, experimental results and theoretical developments of VBS at the Large Hadron Collider, its high luminosity upgrade, and future colliders are presented.
DOI: 10.1016/0370-2693(93)91530-z
1993
Cited 55 times
Quark and gluon distributions and αs from nucleon structure functions at low x
The Q2 dependence of the structure functions F2p and F2d recently measured by the NMC is compared with the predictions of perturbative QCD at next-to-leading order. Good agreement is observed, leading to accurate determinations of the quark and gluon distributions in the range 0.008 ⩽ × ⩽ 0.5. The strong coupling constant is measured from the low x data; the result agrees with previous determinations.
DOI: 10.1016/j.physletb.2017.03.029
2017
Cited 31 times
Searches for lepton number violation and resonances in K±→πμμ decays
The NA48/2 experiment at CERN collected a large sample of charged kaon decays to final states with multiple charged particles in 2003–2004. A new upper limit on the rate of the lepton number violating decay K±→π∓μ±μ± is reported: B(K±→π∓μ±μ±)<8.6×10−11 at 90% CL. Searches for two-body resonances X in K±→πμμ decays (such as heavy neutral leptons N4 and inflatons χ) are also presented. In the absence of signals, upper limits are set on the products of branching fractions B(K±→μ±N4)B(N4→πμ) and B(K±→π±X)B(X→μ+μ−) for ranges of assumed resonance masses and lifetimes. The limits are in the (10−11,10−9) range for resonance lifetimes below 100 ps.
DOI: 10.1016/j.physletb.2004.08.058
2004
Cited 37 times
Observation of the rare decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msub><mml:mi>K</mml:mi><mml:mi>S</mml:mi></mml:msub><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mi>μ</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>μ</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math>
A search for the decay KS→π0μ+μ− has been made by the NA48/1 Collaboration at the CERN SPS accelerator. The data were collected during 2002 with a high-intensity KS beam. Six events were found with a background expectation of 0.22−0.11+0.18 events. Using a vector matrix element and unit form factor, the measured branching ratio is B(KS→π0μ+μ−)=[2.9−1.2+1.5(stat)±0.2(syst)]×10−9.
DOI: 10.1103/physrevd.86.036011
2012
Cited 22 times
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>W</mml:mi><mml:mi>L</mml:mi></mml:msub><mml:msub><mml:mi>W</mml:mi><mml:mi>L</mml:mi></mml:msub></mml:math>scattering at the LHC: Improving the selection criteria
We present a systematic study of the different mechanisms leading to $WW$ pair production at the Large Hadron Collider (LHC), both in the same-sign and opposite-sign channels, and we emphasize that the former offers much better potential for investigating non-resonant ${W}_{L}{W}_{L}$ scattering. We propose a new kinematic variable to isolate the ${W}_{L}{W}_{L}$ scattering component in same-sign $WW$ production at the LHC. Focusing on purely leptonic $W$ decay channels, we show that it considerably improves the LHC capabilities to shed light on the electroweak symmetry breaking mechanism after collecting $100\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data at $\sqrt{s}=14\text{ }\text{ }\mathrm{TeV}$. The new variable is less effective in the opposite-sign $WW$ channel due to different background composition.
DOI: 10.1007/jhep07(2019)021
2019
Cited 15 times
Same-sign WW scattering in the HEFT: discoverability vs. EFT validity
A bstract Vector boson scatterings are fundamental processes to shed light on the nature of the electroweak symmetry breaking mechanism. Deviations from the Standard Model predictions on the corresponding observables can be interpreted in terms of effective field theories, that however undergo consistency conditions. In this paper, the same-sign WW scattering is considered within the HEFT context and the correct usage of the effective field theory approach is discussed. Regions of the parameters space are identified where a signal of new physics could be measured at HL-LHC with a significance of more than 5 σ and the effective field theory description is consistently adopted. These results are then translated into bounds on the ξ parameter in the composite Higgs scenario. The discussion on the agreement with previous literature and the comparison with the equivalent analysis in the SMEFT case are also included.
DOI: 10.1103/physrevd.104.013003
2021
Cited 12 times
Standard model EFT effects in vector-boson scattering at the LHC
The assumption that the Standard Model is an effective field theory (SM EFT) of a more fundamental theory at a higher (than electroweak) energy scale implies a growth of cross sections for electroweak vector-boson scattering (VBS) processes signaling the appearance of a resonance (or resonances) near that scale. In this article, we investigate in detail SM EFT effects from dimension-six operators in VBS with like-sign-$W$ production in fully leptonic decay modes at the high-luminosity LHC (HL-LHC). We find that these effects are important for a handful of operators, most notably for the operator composed of three $SU(2)$ field-strength tensors responsible for strong transversely polarized vector-boson interactions. Current global fits on Wilson coefficients allow for an observable signal at the HL-LHC, if not accessible with the current LHC data set.
DOI: 10.1007/jhep03(2024)137
2024
First observation and study of the K± → π0π0μ±ν decay
A bstract The NA48/2 experiment at CERN reports the first observation of the K ± → π 0 π 0 μ ± ν decay based on a sample of 2437 candidates with 15% background contamination collected in 2003–2004. The decay branching ratio in the kinematic region of the squared dilepton mass above 0.03 GeV 2 / c 4 is measured to be (0.65 ± 0.03) × 10 − 6 . The extrapolation to the full kinematic space, using a specific model, is found to be (3.45 ± 0.16) × 10 − 6 , in agreement with chiral perturbation theory predictions.
DOI: 10.1016/s0550-3213(96)90117-0
1996
Cited 33 times
The A dependence of the nuclear structure function ratios
Results are presented for six nuclei from Be to Pb on the structure function ratios F2A/F2C(x) and their A dependence in deep inelastic muon scattering at 200 GeV incident muon energy. The data cover the kinematic range 0.01 < x < 0.8 with Q2 ranging from 2 to 70 GeV2. The A dependence of nuclear structure function ratios is parametrised and compared to various models.
DOI: 10.1016/s0168-9002(03)01508-0
2003
Cited 29 times
Observation of long ionizing tracks with the ICARUS T600 first half-module
Liquid noble gas detectors have driven particle physics research and technology in many sub-fields for many years. Recently their impact as a target and detector medium has been applied to neutrino physics research. As new results and new questions appear in neutrino physics, new detector technologies in general have been explored to keep pace with the requirement of higher statistics, higher precision experiments. Liquid argon time projection chamber devices have emerged as the detector of choice for accelerator based, massive, precision, neutrino detection. In particular, in the last decade, results from test stands and experiments have driven the development of this technology towards large scales. From the MicroBooNE experiment, SBND, and ICARUS on the Short Baseline program at Fermilab to the scale required for the huge DUNE experiment, these detectors are enabling precision neutrino physics for neutrino oscillations. And if history is our guide, as a new detection technology, liquid argon time projection chambers will likely teach us unexpected things.In this paper we present the general features of liquid argon time projection chambers for neutrino physics, a brief history of the technology and details of recent research and development that is driving the design of the detectors under construction. Finally, some comments on future R&D envisioned and the impact of this work on other fields is described.
DOI: 10.1140/epjc/s10052-010-1349-8
2010
Cited 22 times
Measurement of the direct emission and interference terms and search for CP violation in the decay K ±→π ± π 0 γ
We report on the measurement of the direct emission (DE) and interference (INT) terms of the K\pm -> \pi\pm\pi^0 g decay by the NA48/2 experiment at the CERN SPS. From the data collected during 2003 and 2004 about 600k such decay candidates have been selected. The relative amounts of DE and INT with respect to the internal bremsstrahlung (IB) contribution have been measured in the range 0<T*\pi<80 MeV: Frac_{DE} (0<T*\pi<80 MeV) = (3.32\pm 0.15_{stat} \pm 0.14_{sys})x10^{-2} Frac_{INT} (0<T*\pi<80 MeV) = (- 2.35\pm 0.35_{stat} \pm 0.39_{sys})x10^{-2}, where T*pi is the kinetic energy of the charged pion in the kaon rest frame. This is the first observation of an interference term in T*\pi decays. In addition, a limit on the CP violating asymmetry in the K^+ and K^- branching ratios for this channel has been determined to be less than 1.5x10^{-3} at 90% confidence level.
DOI: 10.1016/0370-2693(94)90879-6
1994
Cited 31 times
Quasielastic J/ψ muoproduction from hydrogen, deuterium, carbon and tin
Quasielastic production of J/ψ mesons has been measured in muon interactions with hydrogen, deuterium, carbon and tin targets at incident muon energies of 200 and 280 GeV. The hydrogen and deuterium data were used to study the transverse momentum distribution of the J/ψ's. These data have been analysed together with previously published ϱ0 data in the framework of the vector meson dominance model. The radii of the Jψ and the ϱ0 as well as the total J/ψ-N and ϱ0-N cross sections were deduced. From the tin and carbon data the ratio of the quasielastic J/ψ production cross sections, Rqe(Sn/C), has been extracted and found to be less than unity. In the Glauber approach this suppression can be related to the J/ψ absorption probability in nuclei. The suppression is also compared to those predicted by various colour transparency models.
DOI: 10.1140/epjc/s10052-007-0253-3
2007
Cited 18 times
Measurements of charged kaon semileptonic decay branching fractions K±→π0μ±ν and K±→π0e±ν and their ratio
Measured ratios of decay rates for ${\mathcal{R}}_{K e 3 / K2\pi}$ , ${\mathcal{R}}_{K \mu3 / K2\pi}$ and ${\mathcal{R}}_{K \mu3 / Ke3}$ are presented. These measurements are based on K± decays collected in a dedicated run in 2003 by the NA48/2 experiment at CERN. The results obtained are ${\mathcal{R}}_{K e 3 / K2\pi} = 0.2496\pm0.0009 ({\text{stat}})\pm0.0004 ({\text{syst}})$ and ${\mathcal{R}}_{K \mu3 / K2\pi} = 0.1637\pm0.0006 ({\text{stat}})\pm0.0003 ({\text{syst}})$ . Using the PDG average for the K±→π±π0 normalisation mode, both values are found to be larger than the current values given by the particle data book and lead to a larger magnitude of the |Vus| CKM element than previously accepted. When combined with the latest particle data book value of |Vud|, the result is in agreement with unitarity of the CKM matrix. In addition, a new measured value of ${\mathcal{R}}_{K \mu3 / Ke3} = 0.656\pm0.003({\text{stat}})\pm0.001({\text{syst}})$ is compared to the semi-empirical predictions based on the latest form factor measurements.
DOI: 10.1016/j.physletb.2014.01.038
2014
Cited 12 times
A new measurement of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mo>±</mml:mo></mml:mrow></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mrow><mml:mi>π</mml:mi></mml:mrow><mml:mrow><mml:mo>±</mml:mo></mml:mrow></mml:msup><mml:mi>γ</mml:mi><mml:mi>γ</mml:mi></mml:math> decay at the NA48/2 experiment
The NA48/2 experiment at CERN collected two data samples with minimum bias trigger conditions in 2003 and 2004. A measurement of the rate and dynamic properties of the rare decay K±→π±γγ from these data sets based on 149 decay candidates with an estimated background of 15.5±0.7 events is reported. The model-independent branching ratio in the kinematic range z=(mγγ/mK)2>0.2 is measured to be BMI(z>0.2)=(0.877±0.089)×10−6, and the branching ratio in the full kinematic range assuming a particular Chiral Perturbation Theory description to be B(Kπγγ)=(0.910±0.075)×10−6.
DOI: 10.1016/j.physletb.2007.04.044
2007
Cited 16 times
Measurement of the Dalitz plot slope parameters of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>K</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math> decay
The distribution of the K±→π±π+π− decays in the Dalitz plot has been measured by the NA48/2 experiment at the CERN SPS with a sample of 4.71×108 fully reconstructed events. With the standard Particle Data Group parameterization the following values of the slope parameters were obtained: g=(−21.134±0.017)%, h=(1.848±0.040)%, k=(−0.463±0.014)%. The quality and statistical accuracy of the data have allowed an improvement in precision by more than an order of magnitude, and are such as to warrant a more elaborate theoretical treatment, including pion–pion rescattering, which is in preparation.
DOI: 10.1016/j.physletb.2007.11.075
2008
Cited 15 times
First observation and measurement of the decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>K</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mi>γ</mml:mi></mml:math>
Using the full data set of the NA48/2 experiment, the decay K+- -> pi+- e+ e- gamma is observed for the first time, selecting 120 candidates with 7.3 +- 1.7 estimated background events. With K+- -> pi+- pi0D as normalisation channel, the branching ratio is determined in a model-independent way to be Br(K+- -> pi+- e+ e- gamma, m_eegamma > 260 MeV/c^2) = (1.19 +- 0.12_stat +- 0.04_syst) x 10^-8. This measured value and the spectrum of the e+ e- gamma invariant mass allow a comparison with predictions of Chiral Perturbation Theory.
DOI: 10.1016/j.physletb.2010.02.036
2010
Cited 12 times
Empirical parameterization of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>K</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math> decay Dalitz plot
As first observed by the NA48/2 experiment at the CERN SPS, the π0π0 invariant mass (M00) distribution from K±→π±π0π0 decay shows a cusp-like anomaly at M00=2m+, where m+ is the charged pion mass. An analysis to extract the ππ scattering lengths in the isospin I=0 and I=2 states, a0 and a2, respectively, has been recently reported. In the present work the Dalitz plot of this decay is fitted to a new empirical parameterization suitable for practical purposes, such as Monte Carlo simulations of K±→π±π0π0 decays.
DOI: 10.1016/j.physletb.2018.11.046
2019
Cited 10 times
First observation and study of the K± → π±π0e+e− decay
The NA48/2 experiment at CERN reports the first observation of the K±→π±π0e+e− decay from an exposure of 1.7×1011 charged kaon decays recorded in 2003–2004. A sample of 4919 candidates with 4.9% background contamination allows the determination of the branching ratio in the full kinematic region, BR(K±→π±π0e+e−)=(4.24±0.14)×10−6. The study of the kinematic space shows evidence for a structure dependent contribution in agreement with predictions based on chiral perturbation theory. Several P- and CP-violating asymmetries are also evaluated.
DOI: 10.1140/epjc/s10052-020-7728-x
2020
Cited 8 times
EFT triangles in the same-sign WW scattering process at the HL-LHC and HE-LHC
Abstract We investigate the Beyond Standard Model discovery potential in the framework of the effective field theory (EFT) for the same-sign WW scattering process in purely leptonic W decay modes at the High-Luminosity and High-Energy phases of the Large Hadron Collider (LHC). The goal of this paper is to examine the applicability of the EFT approach, with one dimension-8 operator varied at a time, to describe a hypothetical new physics signal in the WWWW quartic coupling. In the considered process there is no experimental handle on the WW invariant mass, and it has previously been shown that the discovery potential at 14 TeV is rather slim. In this paper we report the results calculated for a 27 TeV machine and compare them with the discovery potential obtained at 14 TeV. We find that while the respective discovery regions shift to lower values of the Wilson coefficients, the overall discovery potential of this procedure does not get significantly larger with a higher beam energy.
DOI: 10.1016/j.physletb.2006.02.011
2006
Cited 15 times
Search for direct CP violation in the decays <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>K</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:mn>3</mml:mn><mml:msup><mml:mi>π</mml:mi><mml:mo>±</mml:mo></mml:msup></mml:math>
We report a measurement of the direct CP violation asymmetry parameter $A_g$ in charged kaon decays $K^\pm\to\pi^\pm\pi^+\pi^-$ by the NA48/2 experiment at the CERN SPS. The experiment has been designed not to be limited by systematics in the asymmetry measurement. Using $1.67\times 10^9$ such decays collected during the 2003 run, the charge asymmetry in the Dalitz plot linear slope parameter $g$ has been measured to be $A_g=(1.7\pm2.9)\times 10^{-4}$. The precision of the result is limited by the statistics used.
DOI: 10.1016/j.nima.2009.07.099
2009
Cited 10 times
First measurements of the performance of the Barrel RPC system in CMS
During the summer 2006, a first integrated test of a part of the CMS experiment was performed at CERN collecting a data sample of several millions of cosmic rays events. A fraction of the Resistive Plate Chambers system was successfully operated. Results on the RPC performance are reported.
DOI: 10.1016/j.physletb.2006.05.008
2006
Cited 11 times
Search for direct CP-violation in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:msup><mml:mi>K</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo>±</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math> decays
A search for direct CP-violation in K±→π±π0π0 decay based on 47.14 million events has been performed by the NA48/2 experiment at the CERN SPS. The asymmetry in the Dalitz plot linear slopes Ag=(g+−g−)/(g++g−) is measured to be Ag=(1.8±2.6)×10−4. The design of the experiment and the method of analysis provide good control of instrumental charge asymmetries in this measurement. The precision of the result is limited by statistics and is almost one order of magnitude better than that of previous measurements by other experiments.
DOI: 10.1007/jhep08(2014)159
2014
Cited 6 times
Detailed study of the K ± → π 0 π 0 e ± ν (K e4 00 ) decay properties
A sample of 65210 K ± → π 0 π 0 e ± ν (K e4 00 ) decay candidates with 1% background contamination has been collected in 2003-2004 by the NA48/2 collaboration at the CERN SPS. A study of the differential rate provides the first measurement of the hadronic form factor variation in the plane (M 2 , M 2 ) and brings evidence for a cusp-like structure in the distribution of the squared π 0 π 0 invariant mass around $$ 4{m}_{\pi^{+}}^2 $$ . Exploiting a model independent description of this form factor, the branching ratio, inclusive of radiative decays, is obtained using the K ± → π 0 π 0 π ± decay mode as normalization. It is measured to be BR(K e4 00 ) = (2.552 ± 0.010stat ± 0.010syst ± 0.032ext) × 10−5, which improves the current world average precision by an order of magnitude while the 1.4% relative precision is dominated by the external uncertainty from the normalization mode. A comparison with the properties of the corresponding mode involving a π + π − pair (K e4 + − ) is also presented.
DOI: 10.1007/jhep10(2018)150
2018
Cited 6 times
Measurement of the form factors of charged kaon semileptonic decays
A bstract A measurement of the form factors of charged kaon semileptonic decays is presented, based on 4.4 × 10 6 K ± → π 0 e ± ν e ( K e 3 ± ) and 2.3 × 10 6 K ± → π 0 μ ± ν μ ( K μ 3 ± ) decays collected in 2004 by the NA48/2 experiment. The results are obtained with improved precision as compared to earlier measurements. The combination of measurements in the K e 3 ± and K μ 3 ± modes is also presented.
DOI: 10.48550/arxiv.hep-ex/0103008
2001
Cited 11 times
The ICARUS Experiment, A Second-Generation Proton Decay Experiment and Neutrino Observatory at the Gran Sasso Laboratory
The final phase of the ICARUS physics program requires a sensitive mass of liquid Argon of 5000 tons or more. The T600 detector stands today as the first living proof that such large detector can be built and that liquid Argon imaging technology can be implemented on such large scales. After the successful completion of a series of technical tests to be performed at the assembly hall in Pavia, the T600 detector will be ready to be transported into the LNGS tunnel. The operation of the T600 at the LNGS will allow us (1) to develop the local infrastructure needed to operate our large detector (2) to start the handling of the underground liquid argon technology (3) to study the local background (4) to start the data taking with an initial liquid argon mass that will reach in a 5-6 year program the multi-kton goal. The T600 is to be considered as the first milestone on the road towards a total sensitive mass of 5000 tons: it is the first piece of the detector to be complemented by further modules of appropriate size and dimensions, in order to reach in a most efficient and rapid way the final design mass. In this document, we describe the physics program that will be accomplished within the first phase of the program.
DOI: 10.1016/j.physletb.2010.10.008
2011
Cited 4 times
Precision measurement of the ratio <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:mi mathvariant="normal">BR</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mi>K</mml:mi><mml:mi mathvariant="normal">S</mml:mi></mml:msub><mml:mo>→</mml:mo><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>π</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><…
The KS→π+π−e+e− decay mode was investigated using the data collected in 2002 by the NA48/1 Collaboration. With about 23 k KS→π+π−e+e− events and 59 k KL→π+π−πD0 normalization decays, the KS→π+π−e+e− branching ratio relative to the KL→π+π−πD0 one was determined to be BR(KS→π+π−e+e−)/BR(KL→π+π−πD0)=(3.28±0.06stat±0.04syst)×10−2. This result was used to set the upper limit |gE1/gBR|<3.0 at 90% CL on the presence, in the decay amplitude, of an E1 direct emission (gE1) term relative to the dominant inner bremsstrahlung (gBR) term. The CP-violating asymmetry Aϕ in the sinϕcosϕ distribution of KS→π+π−e+e− events, where ϕ is the angle between the π+π− and the e+e− decay planes in the kaon centre of mass, was found to be Aϕ=(−0.4±0.8)%, consistent with zero. These results are in good agreement with a description of the KS→π+π−e+e− decay amplitude dominated by the CP-even inner bremsstrahlung process.
2012
Cited 4 times
New measurement of the K±→π+π−e±ν (Ke4) decay branching ratio and hadronic form factors
Abstract A sample of more than one million K ± → π + π − e ± ν ( K e 4 ) decay candidates with less than one percent background contamination has been collected by the NA48/2 experiment at the CERN SPS in 2003–2004, allowing a detailed study of the decay properties. The branching ratio, inclusive of K e 4 γ decays, is measured to be BR ( K e 4 ) = ( 4.257 ± 0.016 exp ± 0.031 ext ) × 10 − 5 with a total relative error of 0.8 % . This measurement complements the study of S- and P-wave hadronic form factors by assigning absolute values to the relative hadronic form factors obtained earlier in a simultaneous analysis of the ππ scattering lengths conducted on the same data sample. The overall form factor normalization f s = 5.705 ± 0.017 exp ± 0.031 ext is obtained with a total relative precision of 0.6 % .
2006
Cited 6 times
Observation of a cusp-like structure in the π0π0 invariant mass distribution from K±→π±π0π0 decay and determination of the ππ scattering lengths
Abstract We report the results from a study of a partial sample of ∼ 2.3 × 10 7 K ± → π ± π 0 π 0 decays recorded by the NA48/2 experiment at the CERN SPS, showing an anomaly in the π 0 π 0 invariant mass ( M 00 ) distribution in the region around M 00 = 2 m + , where m + is the charged pion mass. This anomaly, never observed in previous experiments, can be interpreted as an effect due mainly to the final state charge exchange scattering process π + π − → π 0 π 0 in K ± → π ± π + π − decay [N. Cabibbo, Phys. Rev. Lett. 93 (2004) 121801]. It provides a precise determination of a 0 − a 2 , the difference between the ππ scattering lengths in the isospin I = 0 and I = 2 states. A best fit to a rescattering model [N. Cabibbo, G. Isidori, JHEP 0503 (2005) 21] corrected for isospin symmetry breaking gives ( a 0 − a 2 ) m + = 0.268 ± 0.010 ( stat ) ± 0.004 ( syst ) , with additional external uncertainties of ±0.013 from branching ratio and theoretical uncertainties. If the correlation between a 0 and a 2 predicted by chiral symmetry is taken into account, this result becomes ( a 0 − a 2 ) m + = 0.264 ± 0.006 ( stat ) ± 0.004 ( syst ) ± 0.013 ( ext ) .
DOI: 10.1016/j.nima.2008.12.092
2009
Cited 4 times
Resistive plate chamber commissioning and performance in CMS
The CMS muon system is conceived for trigger and muon track reconstruction. The redundancy and robustness of the system are guaranteed by three complementary subsystems: drift tube in the barrel, cathode strip chamber in the end-cap and resistive plate chamber in barrel and end-cap. The installation of muon stations and read-out trigger electronic has been completed in middle 2007. Since than, a remarkable effort has been addressed to the detector commissioning in order to ensure the readiness of the hardware/software chain for the LHC start up operation. At the end of 2007, a test of an entire CMS slice has been performed, involving about 5% of muon stations. Several thousand cosmic muons events have been collected. Performance of the barrel chambers are reported.
2014
Cited 3 times
The Higgs boson and the physics of $WW$ scattering before and after Higgs discovery
This work presents a comprehensive overview of the physics of vector boson scattering (VBS) in the dawn of Run 2 of the Large Hadron Collider (LHC). Recalled here are some of its most basic physics principles, the historical relation between vector boson scattering and the Higgs boson, then discussed is the physics of VBS processes after Higgs discovery, and the prospects for future VBS measurements at the LHC and beyond. This monograph reviews the work of many people, including previously published theoretical work as well as experimental results, but also contains a portion of original simulation-based studies that have not been published before.
DOI: 10.48550/arxiv.hep-ex/0110032
2001
Cited 7 times
Neutrino Oscillations Experiments using Off-axis NuMI Beam
NuMI neutrino beam is constructed to aim at the MINOS detector in Soudan mine. Neutrinos emitted at angles $10-20 mrad$ with respect to the beam axis create an intense beam with a well defined energy, dependent on the angle. Additional surface detectors positioned at the transverse distance of several kilometers from the mine offer an opportunity for very precise mesurements of the neutrino oscillation parameters. The mixing matrix element $|U_{e3}|^{2}$ can be measured down to a value of 0.0025 with the exposure of the order of $20 kton\times years$.
DOI: 10.1016/j.nima.2003.10.001
2004
Cited 5 times
Erratum to “Observation of long ionizing tracks with the ICARUS T600 first half-module” [Nucl. Instr. and Meth. A 508 (2003) 287–294]
DOI: 10.48550/arxiv.2310.20295
2023
First observation and study of the $K^{\pm} \rightarrow π^{0} π^{0} μ^{\pm} ν$ decay
The NA48/2 experiment at CERN reports the first observation of the $K^{\pm} \rightarrow \pi^{0} \pi^{0} \mu^{\pm} \nu$ decay based on a sample of 2437 candidates with 15% background contamination collected in 2003--2004. The decay branching ratio in the kinematic region of the squared dilepton mass above $0.03$~GeV$^2/c^4$ is measured to be $(0.65 \pm 0.03) \times 10^{-6}$. The extrapolation to the full kinematic space, using a specific model, is found to be $(3.45 \pm 0.16) \times 10^{-6}$, in agreement with chiral perturbation theory predictions.
DOI: 10.1016/j.nima.2009.06.092
2010
Resistive Plate Chambers performance with Cosmic Rays in the CMS experiment
The Resistive Plate Chambers [M. Abbrescia, et al., Nucl. Instr. and Meth. A 550 (2005) 116] are used in the CMS experiment [CMS Collaboration, The CMS experiment at the CERN LHC 2008, J. Inst. 3 (2008) S08004] as a dedicated muon trigger both in barrel and endcap system. About 4000m2 of double gap RPCs have been produced and have been installed in the experiment since more than one and half Years. The full barrel system and a fraction of the endcaps have been monitored to study dark current behaviour and system stability, and have been extensively commissioned with Cosmic Rays collected by the full CMS experiment.
DOI: 10.48550/arxiv.2004.00726
2020
VBSCan Mid-Term Scientific Meeting
This document summarises the talks and discussions happened during the VBSCan Mid-Term Scientific Meeting workshop. The VBSCan COST action is dedicated to the coordinated study of vector boson scattering (VBS) from the phenomenological and experimental point of view, for the best exploitation of the data that will be delivered by existing and future particle colliders.
2013
New Measurement of the Charged Kaon Semileptonic $K^\pm \to \pi^ \pi^- E^\pm\nu$ ($K_E4$) Decay Branching Ratio and Hadronic Form Factors
A sample of more than one million K±→π+π−e±ν ( Ke4 ) decay candidates with less than one percent background contamination has been collected by the NA48/2 experiment at the CERN SPS in 2003–2004, allowing a detailed study of the decay properties. The branching ratio, inclusive of Ke4γ decays, is measured to be BR(Ke4)=(4.257±0.016exp±0.031ext)×10−5 with a total relative error of 0.8% . This measurement complements the study of S- and P-wave hadronic form factors by assigning absolute values to the relative hadronic form factors obtained earlier in a simultaneous analysis of the ππ scattering lengths conducted on the same data sample. The overall form factor normalization fs=5.705±0.017exp±0.031ext is obtained with a total relative precision of 0.6% .
DOI: 10.48550/arxiv.1412.8367
2014
The Higgs boson and the physics of $WW$ scattering before and after Higgs discovery
This work presents a comprehensive overview of the physics of vector boson scattering (VBS) in the dawn of Run 2 of the Large Hadron Collider (LHC). Recalled here are some of its most basic physics principles, the historical relation between vector boson scattering and the Higgs boson, then discussed is the physics of VBS processes after Higgs discovery, and the prospects for future VBS measurements at the LHC and beyond. This monograph reviews the work of many people, including previously published theoretical work as well as experimental results, but also contains a portion of original simulation-based studies that have not been published before.
DOI: 10.48550/arxiv.hep-ph/0409208
2004
NMSSM Higgs Detection: LHC, LC, $\gam C$ Collider Complementarity and Higgs-to-Higgs Decays
We discuss the importance of being able to detect Higgs-to-Higgs-pair decays in the context of the Next-to-Minimal Supersymmetric Model (NMSSM) and demonstrate the excellent capabilities of a photon collider for this purpose.
DOI: 10.1063/1.3322484
2010
THE CMS RPC SYSTEM OVERVIEW
The Muon System of the CMS experiment at CERN employees three different detector technologies—Drift Tube Chambers (DT) in the barrel part, Cathode Strip Chambers (CSC) in the endcaps and Resistive Plate Chambers (RPC) both in the barrel and the endcaps. TDs and CSCs serve as precise muon trajectory measurement devices. The RPCs are responsible for the bunch crossing identification and for a fast muon transverse momentum measurement. The total number of RPCs is 480 in the barrel and 756 in the endcaps, covering an area of about 3500 square meters. A brief overview of the system will be presented as well as some recent results about the system stability and performance.
2018
VBSCan Thessaloniki 2018 Workshop Summary
This document reports the first year of activity of the VBSCan COST Action network, as summarised by the talks and discussions happened during the VBSCan Thessaloniki 2018 workshop. The VBSCan COST action is aiming at a consistent and coordinated study of vector-boson scattering from the phenomenological and experimental point of view, for the best exploitation of the data that will be delivered by existing and future particle colliders.
DOI: 10.1140/epjc/s10052-007-0454-9
2007
Measurements of charged kaon semileptonic decay branching fractions K±→π0μ±ν and K±→π0e±ν and their ratio
In an earlier paper [1], the background for Ke3 was over estimated due to an erroneous calculation of the electron identification efficiency. The correct ratios of the partial widths involving this channel are $\mathcal{R}_{K e 3 / K2\pi} = 0.2470\pm0.0009\, ({\text{stat}})\pm0.0004\, ({\text{syst}})$ and $\mathcal{R}_{K \mu3 / Ke3} = 0.663\pm0.003\,({\text{stat}})\pm0.001\,({\text{syst}})$ . Assuming the PDG value [2] for the K2π branching ratio, the measured branching fraction of Br (Ke3) continues to exceed the current PDG value [2]. The extracted value of |Vus|f+(0) is in agreement with the CKM unitary prediction; thus, our conclusions in [1] do not change.
2019
VBSCan Mid-Term Scientific Meeting
This document summarises the talks and discussions happened during the VBSCan Mid-Term Scientific Meeting workshop. The VBSCan COST action is dedicated to the coordinated study of vector boson scattering (VBS) from the phenomenological and experimental point of view, for the best exploitation of the data that will be delivered by existing and future particle colliders.
DOI: 10.22323/1.382.0023
2020
EFT validity issues in Vector Boson Scattering processes
Vector Boson Scattering (VBS) processes are regarded as the best lab to study the VVVV quartic couplings, where V = W, Z.Such studies are carried in the framework of Effective Field Theories (EFT), but the EFT formalism is often not used in a fully consistent way.We discuss the limitations of the EFT approach to describe New Physics effects in VBS data.We argue that the "clipping" technique is the most theory-motivated way to do data analysis in the EFT language and discuss first results from an analysis of CMS Run 2 data on the W Z and same-sign WW process, with and without "clipping" implemented.
2002
Neutrino oscillations with a proton driver upgrade and an off-axis detector: A Case study
We study the physics capabilities of the NuMI beamline with an off-axis highly-segmented iron scintillator detector and with the inclusion of the currently under study proton driver upgrade. We focus on the prospects for the experimental determination of the remaining neutrino oscillation parameters, assuming different outcomes for experiments under way or in preparation. An optimization of the beam conditions and detector location for the detection of the nu_mu to nu_e transitions is discussed. Different physics scenarios were considered, depending on the actual solution of the solar neutrino puzzle. If KamLAND measures Delta m^2_solar, we find it possible to measure both |U_{e3}|^2 and the CP violating phase delta within a viable exposure time, assuming a realistic detector and a complete data analysis. Exposure to both neutrino and antineutrino beams is necessary. We can, in addition, shed light on Delta m^2_solar if its value is at the upper limit of KamLAND sensitivity (i.e. the precise value of Delta m^2_solar remains unknown even after KamLAND). If the solar neutrino solution is not in the LMA region, we can measure |U_{e3}|^2 and determine the neutrino mass hierarchy. The existence of the proton driver is vital for the feasibility of most of these measurements.
2021
arXiv : Vector Boson Scattering Processes: Status and Prospects
Insight into the electroweak (EW) and Higgs sectors can be achieved through measurements of vector boson scattering (VBS) processes. The scattering of EW bosons are rare processes that are precisely predicted in the Standard Model (SM) and are closely related to the Higgs mechanism. Modifications to VBS processes are also predicted in models of physics beyond the SM (BSM), for example through changes to the Higgs boson couplings to gauge bosons and the resonant production of new particles. In this review, experimental results and theoretical developments of VBS at the Large Hadron Collider, its high luminosity upgrade, and future colliders are presented.
DOI: 10.1142/s0217751x05031216
2005
SEARCH FOR THE NMSSM HIGGS BOSONS AT THE PHOTON COLLIDER
A light, Standard Model-like Higgs scalar in the NMSSM will decay predominantly into a pair of Higgs pseudoscalars, these decaying into a four-fermion final state. We study the potential of the CLIC Higgs Experiment to detect such scenario via the search for the final states [Formula: see text] and [Formula: see text]. We find excellent prospects for the observation of the Higgs peak in both channels.
DOI: 10.48550/arxiv.1408.0585
2014
Recent NA48/2 and NA62 results
The NA48/2 Collaboration at CERN has accumulated and analysed unprecedented statistics of rare kaon decays in the $K_{e4}$ modes: $K_{e4}(+-)$ ($K^\pm \to π^+ π^- e^\pm ν$) and $K_{e4}(00)$ ($K^\pm \to π^0 π^0 e^\pm ν$) with nearly one percent background contamination. It leads to the improved measurement of branching fractions and detailed form factor studies. New final results from the analysis of 381 $K^\pm \to π^\pm γγ$ rare decay candidates collected by the NA48/2 and NA62 experiments at CERN are presented. The results include a decay rate measurement and fits to Chiral Perturbation Theory (ChPT) description.
2015
First observation and study of $K^\pm \to \pi^\pm \pi^0 e^+ e^-$ decay at the NA48/2 experiment
DOI: 10.48550/arxiv.hep-ex/0110001
2001
Neutrino Spectrum at the Far Detector
Neutrino oscillation experiments often employ two identical detectors to minimize errors due to inadequately known neutrino beam. We examine various systematics effects related to the prediction of the neutrino spectrum in the `far' detector on the basis of the spectrum observed at the `near' detector. We propose a novel method of the derivation of the far detector spectrum. This method is less sensitive to the details of the understanding of the neutrino beam line and the hadron production spectra than the usually used `double ratio' method thus allowing to reduce the systematic errors.
2001
Neutrino spectrum at the far detector systematic errors
Neutrino oscillation experiments often employ two identical detectors to minimize errors due to inadequately known neutrino beam. We examine various systematics effects related to the prediction of the neutrino spectrum in the `far' detector on the basis of the spectrum observed at the `near' detector. We propose a novel method of the derivation of the far detector spectrum. This method is less sensitive to the details of the understanding of the neutrino beam line and the hadron production spectra than the usually used `double ratio' method thus allowing to reduce the systematic errors.
DOI: 10.5506/aphyspolb.44.1603
2013
Selected experimental results related to heavy-ion physics, obtained using the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC), are presented.Measurements have been performed for lead-lead (PbPb), proton-lead (pPb) and proton-proton (pp) data samples collected in the years 2010-2012.The jet-quenching phenomenon has been studied by looking at the production of the so-called "hard probes", such as high transverse momentum charged particles, isolated photons, Z and W bosons, and jets.In addition, the suppression of quarkonium states and long-range two-particle correlations have been investigated.
DOI: 10.2172/1035135
2012
Ground Motion Studies at NuMI
Ground motion can cause significant deterioration in the luminosity of a linear collider. Vibration of numerous focusing magnets causes continuous misalignments, which makes the beam emittance grow. For this reason, understanding the seismic vibration of all potential LC sites is essential and related efforts in many sites are ongoing. In this document we summarize the results from the studies specific to Fermilab grounds as requested by the LC project leader at FNAL, Shekhar Mishra in FY04-FY06. The Northwestern group focused on how the ground motion effects vary with depth. Knowledge of depth dependence of the seismic activity is needed in order to decide how deep the LC tunnel should be at sites like Fermilab. The measurements were made in the NuMI tunnel, see Figure 1. We take advantage of the fact that from the beginning to the end of the tunnel there is a height difference of about 350 ft and that there are about five different types of dolomite layers. The support received allowed to pay for three months of salary of Michal Szleper. During this period he worked a 100% of his time in this project. That include one week of preparation: 2.5 months of data taking and data analysis during the full period of the project in order to guarantee that we were recording high quality data. We extended our previous work and made more systematic measurements, which included detailed studies on stability of the vibration amplitudes at different depths over long periods of time. As a consequence, a better control and more efficient averaging out of the daytime variation effects were possible, and a better study of other time dependences before the actual depth dependence was obtained. Those initial measurements were made at the surface and are summarized in Figure 2. All measurements are made with equipment that we already had (two broadband seismometers KS200 from GEOTECH and DL-24 portable data recorder). The offline data analysis took advantage of the full Fourier spectra information and the noise was properly subtracted. The basic formalism is summarized if Figure 3. The second objective was to make a measurement deeper under ground (Target hall, Absorber hall and Minos hall - 150 ft to 350 ft), which previous studies did not cover. All results are summarized in Figure 3 and 4. The measurements were covering a frequency range between 0.1 to 50 Hz. The data was taken continuously for at least a period of two weeks in each of the locations. We concluded that the dependence on depth is weak, if any, for frequencies above 1 Hz and not visible at all at lower frequencies. Most of the attenuation (factor of about 2-3) and damping of ground motion that is due to cultural activity at the surface is not detectable once we are below 150 ft underground. Therefore, accelerator currently under consideration can be build at the depth and there is no need to go deeper underground is built at Fermi National Laboratory.
DOI: 10.2172/1155669
2002
Physics potential at FNAL with stronger proton sources
for $$\nu_e$$ appearance at a new location slightly off the axis defined by the MINOS experiment, that new experiment would be ideal for making the next important steps in lepton flavor studies, namely, the search for $$\nu_\mu \to \nu_e$$ at the atmospheric mass splitting, and CP violations. The report concludes with a summary of proton economics and demands for increased proton intensity for the Booster and Main Injector: what the proton source at Fermilab can currently supply, and what adiabatic changes could be implemented to boost the proton supply on the way from here to a proton driver upgrade.
2010
Accurate measurement of F-2(d)/F-2(p) and R(d)-R(p)
Results are presented for F-2(d)/F-2(p) and R(d) - R(p) from simultaneous measurements of deep inelastic muon scattering on hydrogen and deuterium targets, at 90, 120, 200 and 280 GeV. The difference R(d) - R(p), determined in the range 0.002 0.1 the ratio decreases with Q(2).
2009
Elektroniczny system trygera mionowego RPC w eksperymencie CMS dla akceleratora LHC
2009
Electronic system of the RPC Muon Trigger in CMS experiment at LHC accelerator (Elektroniczny system trygera mionowego RPC w eksperymencie CMS akceleratora LHC
2018
VBSCan Thessaloniki 2018 Workshop Summary
This document reports the first year of activity of the VBSCan COST Action network, as summarised by the talks and discussions happened during the VBSCan Thessaloniki 2018 workshop. The VBSCan COST action is aiming at a consistent and coordinated study of vector-boson scattering from the phenomenological and experimental point of view, for the best exploitation of the data that will be delivered by existing and future particle colliders.
2018
VBSCan Thessaloniki 2018 Workshop Summary
This document reports the first year of activity of the VBSCan COST Action network, as summarised by the talks and discussions happened during the VBSCan Thessaloniki 2018 workshop. The VBSCan COST action is aiming at a consistent and coordinated study of vector-boson scattering from the phenomenological and experimental point of view, for the best exploitation of the data that will be delivered by existing and future particle colliders.
DOI: 10.48550/arxiv.1906.11332
2019
VBSCan Thessaloniki 2018 Workshop Summary
This document reports the first year of activity of the VBSCan COST Action network, as summarised by the talks and discussions happened during the VBSCan Thessaloniki 2018 workshop. The VBSCan COST action is aiming at a consistent and coordinated study of vector-boson scattering from the phenomenological and experimental point of view, for the best exploitation of the data that will be delivered by existing and future particle colliders.
2006
High precision study of CP-violating charge asymmetry in K+- ---> 3pi+- decays by the NA-48/2 experiment at CERN
2006
High precision search for direct CP-violation in K+- ---> pi+- pi0 pi0 decays by the NA-48/2 experiment at CERN
DOI: 10.1063/1.2220354
2006
NA48/2 Results on Charged Semileptonic Decays
We present preliminary results of the measurements of charged semileptonic decays K± → π0e±v and K± → π0μ±v. Both measurements indicate higher branching fractions for the corresponding decays than the current PDG values. Consequently, the CKM mixing matrix parameter Vus will increase accordingly. In addition, a precision measurement of the ratio Br(Kμ3±)/Br(Ke3±) confirms the theoretical prediction.
2004
NMSSM Higgs detection: LHC, LC, gamma C collider complementarity and Higgs-to-Higgs decays
2006
Observation of a cusp-like structure in the π0 π0 invariant mass distribution from K± -> π+ π0 π0 decay and determination of the π π scattering lenghts, PHYSICS LETTERS B, num. 633, vol. B, pp. 173-182, 2006
2004
Explicit CP Violation in the Higgs Sector at Future Colliders
2004
Search for the NMSSM Higgs boson at Photon Colliders
DOI: 10.1016/s0168-9002(03)00693-4
2003
Spin structure functions in neutrino scattering experiments
Neutrino scattering experiments using high-intensity neutrino sources can provide useful information to understand the spin structure of the nucleon. Individual quark contributions to the nucleon spin can be disentangled. Gluon contribution to the nucleon spin can be also studied. A thin polarized target comprised of iced HD is proposed.
DOI: 10.1088/0954-3899/29/8/372
2003
Hadron production uncertainties at NuMI
An improved approach for the extrapolation of the neutrino spectrum from the near to the far site is described. The method exploits the strong correlation between neutrino spectra at two arbitrary detector locations, provided that they come from the same parent hadron beam. Accuracy of the method was extensively studied on the particular example of hadron production uncertainties. Neutrino flux at the far on-axis site can be predicted more accurately than in the Far/Near ratio method. In an off-axis experiment, the integrated neutrino flux can be known to be 1–2%, even using only the on-axis near detector information. The off-axis intrinsic νe flux can be estimated to be 5% by correlating it to the νμ and μ flux measured in an on-axis detector.
2003
Detector R&D for future Neutrino Experiments with the NuMI Beamline
A report to the Fermilab Director from the Study Group on Future Neutrino Experiments at Fermilab
DOI: 10.1007/978-981-33-4408-2_122
2021
Same Sign WW Studies Using EFT at LHC
Study ofChaudhary, Geetanjali discovery potential of newKalinowski, Jan physics in the Effective Field Theory (EFT) frameworkKaur, Manjit for the same-sign WW Vector Boson Scattering (VBS) processKozów, Paweł at the High-Luminosity (HL) andSandeep, Kaur High-Energy Large Hadron Collider (HE-LHC) is doneSzleper, Michał. We focus on purely leptonicTkaczyk, Sławomir decays of the W and as a final state in proton-proton collisions, look for $$pp \rightarrow 2jets$$ + $$W^{+}W^{+}$$ $$\rightarrow j j l^{+} \nu l^{'+} \nu ^{'}$$ decay at the LHC and the WW invariant mass cannot be determined experimentally. We study the effect of a single dim-8 operator that alters WWWW quartic gauge coupling and for hints of new physics, we look for the deviations from the Standard Model case. Work at 27 TeV at HE-LHC is reported for both positive and negative values of operators and is compared with previously done work at 14 TeV with 3 $$ab^{-1}$$ luminosity. In this paper, we present comparison results for two dim-8 operators. It is observed that discovery regions for the individual dim-8 operators at HE-LHC shift to lower values of the Wilson coefficients but the overall discovery potential does not get significantly enhanced.
DOI: 10.48550/arxiv.hep-ex/0304017
2003
Detector R&amp;D for future Neutrino Experiments with the NuMI Beamline
A report to the Fermilab Director from the Study Group on Future Neutrino Experiments at Fermilab
DOI: 10.1142/9789812778123_0032
2002
MEASUREMENT OF DIRECT CP VIOLATION BY NA48 AT CERN
DOI: 10.48550/arxiv.hep-ph/0204208
2002
Neutrino Oscillations with a Proton Driver Upgrade and an Off-Axis Detector: A Case Study
We study the physics capabilities of the NuMI beamline with an off-axis highly-segmented iron scintillator detector and with the inclusion of the currently under study proton driver upgrade. We focus on the prospects for the experimental determination of the remaining neutrino oscillation parameters, assuming different outcomes for experiments under way or in preparation. An optimization of the beam conditions and detector location for the detection of the nu_mu to nu_e transitions is discussed. Different physics scenarios were considered, depending on the actual solution of the solar neutrino puzzle. If KamLAND measures Delta m^2_solar, we find it possible to measure both |U_{e3}|^2 and the CP violating phase delta within a viable exposure time, assuming a realistic detector and a complete data analysis. Exposure to both neutrino and antineutrino beams is necessary. We can, in addition, shed light on Delta m^2_solar if its value is at the upper limit of KamLAND sensitivity (i.e. the precise value of Delta m^2_solar remains unknown even after KamLAND). If the solar neutrino solution is not in the LMA region, we can measure |U_{e3}|^2 and determine the neutrino mass hierarchy. The existence of the proton driver is vital for the feasibility of most of these measurements.
DOI: 10.48550/arxiv.hep-ex/0206025
2002
Physics Potential at FNAL with Stronger Proton Sources
This document is the second in a series of reports on the exciting physics that would be accessible at Fermilab in the event of an upgraded proton source. Where the first report covered a broad range of topics, this report focuses specifically on three areas of study: there are brief discussions on the new measurements one could make in both the neutron and anti-proton sectors, and then a detailed discussion of what could be achieved in the neutrino oscillation sector using an upgraded proton source to supply the NuMI beamline with more protons. If one places a new detector optimized for $ν_e$ appearance at a new location slightly off the axis defined by the MINOS experiment, that new experiment would be ideal for making the next important steps in lepton flavor studies, namely, the search for $ν_μ\to ν_e$ at the atmospheric mass splitting, and CP violations. The report concludes with a summary of proton economics and demands for increased proton intensity for the Booster and Main Injector: what the proton source at Fermilab can currently supply, and what adiabatic changes could be implemented to boost the proton supply on the way from here to a proton driver upgrade.
1995
The structure function ratios F Li 2 /(F D 2 ) andF C 2 /(F D 2 ) at small x
1995
The structure function ratios F L i 2 F D 2 andF C 2 F D 2 at small x
1995
Nuclear structure functions from NMC