D. Pitzl

The first measurement of lepton-jet momentum imbalance and azimuthal correlation in lepton-proton scattering at high momentum transfer is presented. These data, taken with the H1 detector at HERA, are corrected for detector effects using an unbinned machine learning algorithm (multifold), which considers eight observables simultaneously in this first application. The unfolded cross sections are compared with calculations performed within the context of collinear or transverse-momentum-dependent factorization in quantum chromodynamics as well as Monte Carlo event generators.

Silicon strip detectors and photodiodes were irradiated in an 800 MeV proton beam. The change of the effective doping concentration was monitored by measuring diode C-V curves. Type inversion is observed at a fluence Φ = 1.5 × 1013 cm−2. Further evidence for type inversion is obtained from a study of pulses generated by an infrared LED in silicon strip detectors. A two-level parametrization is used to describe donor removal and acceptor state creation during proton irradiation: Neff = N0 exp(−cφ)−βφ. We measure values of c = (5.5 ± 1.1) × 1014 cm2 and β = (0.031 ± 0.006) cm−1. After type inversion the depletion voltage increases with proton fluence. This may set the limit for the lifetime of silicon detectors at future colliders. However, the occurence of type inversion does not degrade the performance of silicon strip detectors. The effective doping concentration showed a complex post irradiation behaviour. After a short term annealing period the doping concentration increased beyond the value that had been reached immediately after the exposure.

The design, construction and performance of the H1 silicon vertex detector is described. It consists of two cylindrical layers of double-sided, double-metal silicon sensors read out by a custom designed analog pipeline chip. The analog signals are transmitted by optical fibres to a custom-designed ADC board and are reduced on PowerPC processors. Details of the design and construction are given and performance figures from the first data-taking periods are presented.

Abstract Charged particle multiplicity distributions in positron-proton deep inelastic scattering at a centre-of-mass energy $$\sqrt{s}=319$$ <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>319</mml:mn> </mml:mrow> </mml:math> GeV are measured. The data are collected with the H1 detector at HERA corresponding to an integrated luminosity of 136 pb $$^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow /> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> . Charged particle multiplicities are measured as a function of photon virtuality $$Q^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>Q</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:math> , inelasticity y and pseudorapidity $$\eta $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>η</mml:mi> </mml:math> in the laboratory and the hadronic centre-of-mass frames. Predictions from different Monte Carlo models are compared to the data. The first and second moments of the multiplicity distributions are determined and the KNO scaling behaviour is investigated. The multiplicity distributions as a function of $$Q^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>Q</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:math> and the Bjorken variable $$x_{\mathrm{bj}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>x</mml:mi> <mml:mi>bj</mml:mi> </mml:msub> </mml:math> are converted to the hadron entropy $$S_{\mathrm{hadron}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>S</mml:mi> <mml:mi>hadron</mml:mi> </mml:msub> </mml:math> , and predictions from a quantum entanglement model are tested.

Abstract A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities $$5.5&lt;Q^2 &lt;80\,\mathrm {GeV}^2 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>5.5</mml:mn><mml:mo>&lt;</mml:mo><mml:msup><mml:mi>Q</mml:mi><mml:mn>2</mml:mn></mml:msup><mml:mo>&lt;</mml:mo><mml:mn>80</mml:mn><mml:mspace /><mml:msup><mml:mrow><mml:mi>GeV</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msup></mml:mrow></mml:math> and inelasticities $$0.2&lt;y&lt;0.6$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>0.2</mml:mn><mml:mo>&lt;</mml:mo><mml:mi>y</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.6</mml:mn></mml:mrow></mml:math> is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of $$290\,\mathrm {pb}^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>290</mml:mn><mml:mspace /><mml:msup><mml:mrow><mml:mi>pb</mml:mi></mml:mrow><mml:mrow><mml:mo>-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math> . Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of $$Q^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>Q</mml:mi><mml:mn>2</mml:mn></mml:msup></mml:math> . Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective $$Q^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>Q</mml:mi><mml:mn>2</mml:mn></mml:msup></mml:math> -interval are also determined. Previous results of inclusive jet cross sections in the range $$150&lt;Q^2 &lt;15{,}000\,\mathrm {GeV}^2 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>150</mml:mn><mml:mo>&lt;</mml:mo><mml:msup><mml:mi>Q</mml:mi><mml:mn>2</mml:mn></mml:msup><mml:mo>&lt;</mml:mo><mml:mn>15</mml:mn><mml:mo>,</mml:mo><mml:mn>000</mml:mn><mml:mspace /><mml:msup><mml:mrow><mml:mi>GeV</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msup></mml:mrow></mml:math> are extended to low transverse jet momenta $$5&lt;P_\mathrm{T}^\mathrm{jet} &lt;7\,\mathrm {GeV} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>5</mml:mn><mml:mo>&lt;</mml:mo><mml:msubsup><mml:mi>P</mml:mi><mml:mrow><mml:mi>T</mml:mi></mml:mrow><mml:mi>jet</mml:mi></mml:msubsup><mml:mo>&lt;</mml:mo><mml:mn>7</mml:mn><mml:mspace /><mml:mi>GeV</mml:mi></mml:mrow></mml:math> . The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of $$Q^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>Q</mml:mi><mml:mn>2</mml:mn></mml:msup></mml:math> , the strong coupling constant $$\alpha _s(M_Z)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>α</mml:mi><mml:mi>s</mml:mi></mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:msub><mml:mi>M</mml:mi><mml:mi>Z</mml:mi></mml:msub><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math> is determined in next-to-leading order.

A readout chip for silicon strip detectors with analog event pipeline has been fabricated (SACMOS 2 μm technology) and tested. The chip has been designed to operate at the HERA ep collider at a bunch crossing rate of 10.4 MHz. Each channel has a layout width of 44 μm and consists of a fast, low noise, low power preamplifier followed by a switched capacitor analog event pipeline. The preamplifier consists of a single CMOS push-pull gain cell and offers minimal power consumption. A novel feature of our chip is a self-reading architecture that allows the preamplifier to re-read its own pipeline buffers and thus permits a extensive parallel analog signal processing that is digitally controlled. The results from radiation damage tests with 60Co are given for doses up to 240 krad.

The cross section of the diffractive process e + p → e + Xp is measured at a centre-of-mass energy of 318 GeV, where the system X contains at least two jets and the leading final state proton p is detected in the H1 Very Forward Proton Spectrometer. The measurement is performed in photoproduction with photon virtualities Q 2 < 2 GeV2 and in deep-inelastic scattering with 4 GeV2 < Q 2 < 80 GeV2. The results are compared to next- to-leading order QCD calculations based on diffractive parton distribution functions as extracted from measurements of inclusive cross sections in diffractive deep-inelastic scattering.

The strong coupling constant αs is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic ep scattering (DIS) measured at HERA by the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of αs(mZ) at the Z-boson mass mZ are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be αs(mZ)=0.1157(20)exp(29)th . Complementary, αs(mZ) is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value αs(mZ)=0.1142(28)tot obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.

Motivated by the large particle fluences anticipated for the SSC and LHC, we are performing a systematic study of radiation damage to silicon microstrip detectors. Here we report radiation effects on detectors cooled to 0°C (the proposed operating point for a large SSC silicon tracker) including leakage currents and change in depletion voltage. We also present results on the annealing behavior of the radiation damage. Finally, we report results of charge collection measurements of the damaged detectors made with an 241Am α source.

The radiation damage resulting from the large particle fluences predicted at the Superconducting Super Collider induces significant leakage currents in Si detectors. In order to limit these currents, the detectors are operated at reduced temperatures ( approximately 0 degrees C). Results are presented of a study of temperature effects on both the initial radiation damage and the long-term annealing of that damage in Si PIN detectors. Depletion voltage results are reported. The detectors are exposed to approximately 10/sup 14//cm/sup 2/ 650-MeV protons. Very pronounced temperature dependences are observed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

EUDAQ is a generic data acquisition software developed for use in conjunction with common beam telescopes at charged particle beam lines. Providing high-precision reference tracks for performance studies of new sensors, beam telescopes are essential for the research and development towards future detectors for high-energy physics. As beam time is a highly limited resource, EUDAQ has been designed with reliability and ease-of-use in mind. It enables flexible integration of different independent devices under test via their specific data acquisition systems into a top-level framework. EUDAQ controls all components globally, handles the data flow centrally and synchronises and records the data streams. Over the past decade, EUDAQ has been deployed as part of a wide range of successful test beam campaigns and detector development applications.

A measurement is presented of single- and double-differential dijet cross sections in diffractive deep-inelastic ep scattering at HERA using data collected by the H1 experiment corresponding to an integrated luminosity of 290 pb−1. The investigated phase space is spanned by the photon virtuality in the range of 4 < Q 2 < 100 GeV2 and by the fractional proton longitudinal momentum loss x ℙ < 0.03. The resulting cross sections are compared with next-to-leading order QCD predictions based on diffractive parton distribution functions and the value of the strong coupling constant is extracted.

A first measurement is presented of exclusive photoproduction of $$\rho ^0$$ mesons associated with leading neutrons at HERA. The data were taken with the H1 detector in the years 2006 and 2007 at a centre-of-mass energy of $$\sqrt{s}=319$$ GeV and correspond to an integrated luminosity of 1.16 pb $$^{-1}$$ . The $$\rho ^0$$ mesons with transverse momenta $$p_T<1$$ GeV are reconstructed from their decays to charged pions, while leading neutrons carrying a large fraction of the incoming proton momentum, $$x_L>0.35$$ , are detected in the Forward Neutron Calorimeter. The phase space of the measurement is defined by the photon virtuality $$Q^2 < 2$$ GeV $$^2$$ , the total energy of the photon–proton system $$20 < W_{\gamma p}< 100$$ GeV and the polar angle of the leading neutron $$\theta _n < 0.75$$ mrad. The cross section of the reaction $$\gamma p \rightarrow \rho ^0 n \pi ^+$$ is measured as a function of several variables. The data are interpreted in terms of a double peripheral process, involving pion exchange at the proton vertex followed by elastic photoproduction of a $$\rho ^0$$ meson on the virtual pion. In the framework of one-pion-exchange dominance the elastic cross section of photon-pion scattering, $$\sigma ^\mathrm{el}(\gamma \pi ^+ \rightarrow \rho ^0\pi ^+)$$ , is extracted. The value of this cross section indicates significant absorptive corrections for the exclusive reaction $$\gamma p \rightarrow \rho ^0 n \pi ^+$$ .

The Breit frame provides a natural frame to analyze lepton-proton scattering events. In this reference frame, the parton model hard interactions between a quark and an exchanged boson defines the coordinate system such that the struck quark is back-scattered along the virtual photon momentum direction. In Quantum Chromodynamics (QCD), higher order perturbative or non-perturbative effects can change this picture drastically. As Bjorken-$x$ decreases below one half, a rather peculiar event signature is predicted with increasing probability, where no radiation is present in one of the two Breit-frame hemispheres and all emissions are to be found in the other hemisphere. At higher orders in $\alpha_s$ or in the presence of soft QCD effects, predictions of the rate of these events are far from trivial, and that motivates measurements with real data. We report on the first observation of the empty current hemisphere events in electron-proton collisions at the HERA collider using data recorded with the H1 detector at a center-of-mass energy of 319 GeV. The fraction of inclusive neutral-current DIS events with an empty hemisphere is found to be $0.0112 \pm 3.9\,\%_\text{stat} \pm 4.5\,\%_\text{syst} \pm 1.6\,\%_\text{mod}$ in the selected kinematic region of $150< Q^2<1500$ GeV$^2$ and inelasticity $0.14< y<0.7$. The data sample corresponds to an integrated luminosity of 351.1 pb$^{-1}$, sufficient to enable differential cross section measurements of these events. The results show an enhanced discriminating power at lower Bjorken-$x$ among different Monte Carlo event generator predictions.

The H1 Collaboration reports the first measurement of the 1-jettiness event shape observable $\tau_1^b$ in neutral-current deep-inelastic electron-proton scattering (DIS). The observable $\tau_1^b$ is equivalent to a thrust observable defined in the Breit frame. The data sample was collected at the HERA $ep$ collider in the years 2003-2007 with center-of-mass energy of $\sqrt{s}=319\,\text{GeV}$, corresponding to an integrated luminosity of $351.1\,\text{pb}^{-1}$. Triple differential cross sections are provided as a function of $\tau_1^b$, event virtuality $Q^2$, and inelasticity $y$, in the kinematic region $Q^2>150\,\text{GeV}^{2}$. Single differential cross section are provided as a function of $\tau_1^b$ in a limited kinematic range. Double differential cross sections are measured, in contrast, integrated over $\tau_1^b$ and represent the inclusive neutral-current DIS cross section measured as a function of $Q^2$ and $y$. The data are compared to a variety of predictions and include classical and modern Monte Carlo event generators, predictions in fixed-order perturbative QCD where calculations up to $\mathcal{O}(\alpha_s^3)$ are available for $\tau_1^b$ or inclusive DIS, and resummed predictions at next-to-leading logarithmic accuracy matched to fixed order predictions at $\mathcal{O}(\alpha_s^2)$. These comparisons reveal sensitivity of the 1-jettiness observable to QCD parton shower and resummation effects, as well as the modeling of hadronization and fragmentation. Within their range of validity, the fixed-order predictions provide a good description of the data. Monte Carlo event generators are predictive over the full measured range and hence their underlying models and parameters can be constrained by comparing to the presented data.

The H1 Collaboration at HERA reports the first measurement of groomed event shape observables in deep inelastic electron-proton scattering (DIS) at $\sqrt{s}=319$ GeV, using data recorded between the years 2003 and 2007 with an integrated luminosity of $351$ pb$^{-1}$. Event shapes provide incisive probes of perturbative and non-perturbative QCD. Grooming techniques have been used for jet measurements in hadronic collisions; this paper presents the first application of grooming to DIS data. The analysis is carried out in the Breit frame, utilizing the novel Centauro jet clustering algorithm that is designed for DIS event topologies. Events are required to have squared momentum-transfer $Q^2 > 150$ GeV$^2$ and inelasticity $ 0.2 < y < 0.7$. We report measurements of the production cross section of groomed event 1-jettiness and groomed invariant mass for several choices of grooming parameter. Monte Carlo model calculations and analytic calculations based on Soft Collinear Effective Theory are compared to the measurements.

Measurements of normalised cross sections for the production of photons and neutrons at very small angles with respect to the proton beam direction in deep-inelastic $$ep$$ scattering at HERA are presented as a function of the Feynman variable $$x_F$$ and of the centre-of-mass energy of the virtual photon-proton system $$W$$ . The data are taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of $$131~\text {pb}^{-1}$$ . The measurement is restricted to photons and neutrons in the pseudorapidity range $$\eta >7.9$$ and covers the range of negative four momentum transfer squared at the positron vertex $$6<Q^2<100$$ GeV $$^2$$ , of inelasticity $$0.05<y<0.6$$ and of $$70<W<245~$$ GeV. To test the Feynman scaling hypothesis the $$W$$ dependence of the $$x_F$$ dependent cross sections is investigated. Predictions of deep-inelastic scattering models and of models for hadronic interactions of high energy cosmic rays are compared to the measured cross sections.

Abstract Exclusive photoproduction of $${{\rho ^0}} (770)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>ρ</mml:mi> <mml:mn>0</mml:mn> </mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>770</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> mesons is studied using the H1 detector at the ep collider HERA. A sample of about 900,000 events is used to measure single- and double-differential cross sections for the reaction $$\gamma p \rightarrow \pi ^{+}\pi ^{-}Y$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>γ</mml:mi> <mml:mi>p</mml:mi> <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:mi>Y</mml:mi> </mml:mrow> </mml:math> . Reactions where the proton stays intact ( $${{{m_Y}} {=}m_p}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Y</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>p</mml:mi> </mml:msub> </mml:mrow> </mml:math> ) are statistically separated from those where the proton dissociates to a low-mass hadronic system ( $$m_p{&lt;}{{m_Y}} {&lt;}10~{{\text {GeV}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>p</mml:mi> </mml:msub> <mml:mo>&lt;</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Y</mml:mi> </mml:msub> <mml:mo>&lt;</mml:mo> <mml:mn>10</mml:mn> <mml:mspace /> <mml:mtext>GeV</mml:mtext> </mml:mrow> </mml:math> ). The double-differential cross sections are measured as a function of the invariant mass $$m_{\pi \pi }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>m</mml:mi> <mml:mrow> <mml:mi>π</mml:mi> <mml:mi>π</mml:mi> </mml:mrow> </mml:msub> </mml:math> of the decay pions and the squared 4-momentum transfer t at the proton vertex. The measurements are presented in various bins of the photon–proton collision energy $${{W_{\gamma p}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>W</mml:mi> <mml:mrow> <mml:mi>γ</mml:mi> <mml:mi>p</mml:mi> </mml:mrow> </mml:msub> </mml:math> . The phase space restrictions are $$0.5\le m_{\pi \pi } \le 2.2~{{\text {GeV}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>0.5</mml:mn> <mml:mo>≤</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mrow> <mml:mi>π</mml:mi> <mml:mi>π</mml:mi> </mml:mrow> </mml:msub> <mml:mo>≤</mml:mo> <mml:mn>2.2</mml:mn> <mml:mspace /> <mml:mtext>GeV</mml:mtext> </mml:mrow> </mml:math> , $$\vert t\vert \le 1.5~{{\text {GeV}^2}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mrow> <mml:mo>|</mml:mo> <mml:mi>t</mml:mi> <mml:mo>|</mml:mo> </mml:mrow> <mml:mo>≤</mml:mo> <mml:mn>1.5</mml:mn> <mml:mspace /> <mml:msup> <mml:mtext>GeV</mml:mtext> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:math> , and $$20 \le W_{\gamma p} \le 80~{{\text {GeV}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>20</mml:mn> <mml:mo>≤</mml:mo> <mml:msub> <mml:mi>W</mml:mi> <mml:mrow> <mml:mi>γ</mml:mi> <mml:mi>p</mml:mi> </mml:mrow> </mml:msub> <mml:mo>≤</mml:mo> <mml:mn>80</mml:mn> <mml:mspace /> <mml:mtext>GeV</mml:mtext> </mml:mrow> </mml:math> . Cross section measurements are presented for both elastic and proton-dissociative scattering. The observed cross section dependencies are described by analytic functions. Parametrising the $${m_{\pi \pi }}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>m</mml:mi> <mml:mrow> <mml:mi>π</mml:mi> <mml:mi>π</mml:mi> </mml:mrow> </mml:msub> </mml:math> dependence with resonant and non-resonant contributions added at the amplitude level leads to a measurement of the $${{\rho ^0}} (770)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>ρ</mml:mi> <mml:mn>0</mml:mn> </mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>770</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> meson mass and width at $$m_\rho = 770.8{}^{+2.6}_{-2.7}~({\text {tot.}})~{{\text {MeV}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>ρ</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>770.8</mml:mn> <mml:msubsup> <mml:mrow /> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>2.7</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>2.6</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace /> <mml:mrow> <mml:mo>(</mml:mo> <mml:mtext>tot.</mml:mtext> <mml:mo>)</mml:mo> </mml:mrow> <mml:mspace /> <mml:mtext>MeV</mml:mtext> </mml:mrow> </mml:math> and $$\Gamma _\rho = 151.3 {}^{+2.7}_{-3.6}~({\text {tot.}})~{{\text {MeV}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>Γ</mml:mi> <mml:mi>ρ</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>151.3</mml:mn> <mml:msubsup> <mml:mrow /> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>3.6</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>2.7</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace /> <mml:mrow> <mml:mo>(</mml:mo> <mml:mtext>tot.</mml:mtext> <mml:mo>)</mml:mo> </mml:mrow> <mml:mspace /> <mml:mtext>MeV</mml:mtext> </mml:mrow> </mml:math> , respectively. The model is used to extract the $${{\rho ^0}} (770)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>ρ</mml:mi> <mml:mn>0</mml:mn> </mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>770</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> contribution to the $$\pi ^{+}\pi ^{-}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <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:mrow> </mml:math> cross sections and measure it as a function of t and $${W_{\gamma p}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>W</mml:mi> <mml:mrow> <mml:mi>γ</mml:mi> <mml:mi>p</mml:mi> </mml:mrow> </mml:msub> </mml:math> . In a Regge asymptotic limit in which one Regge trajectory $$\alpha (t)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>α</mml:mi> <mml:mo>(</mml:mo> <mml:mi>t</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> dominates, the intercept $$\alpha (t{=}0) = 1.0654\ {}^{+0.0098}_{-0.0067}~({\text {tot.}})$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>α</mml:mi> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>t</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mo>=</mml:mo> <mml:mn>1.0654</mml:mn> <mml:mspace /> <mml:msubsup> <mml:mrow /> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>0.0067</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.0098</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace /> <mml:mrow> <mml:mo>(</mml:mo> <mml:mtext>tot.</mml:mtext> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> and the slope $$\alpha ^\prime (t{=}0) = 0.233 {}^{+0.067 }_{-0.074 }~({\text {tot.}}) ~{{\text {GeV}^{-2}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>α</mml:mi> <mml:mo>′</mml:mo> </mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>t</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mo>=</mml:mo> <mml:mn>0.233</mml:mn> <mml:msubsup> <mml:mrow /> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>0.074</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.067</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace /> <mml:mrow> <mml:mo>(</mml:mo> <mml:mtext>tot.</mml:mtext> <mml:mo>)</mml:mo> </mml:mrow> <mml:mspace /> <mml:msup> <mml:mtext>GeV</mml:mtext> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> of the t dependence are extracted for the case $$m_Y{=}m_p$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Y</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>p</mml:mi> </mml:msub> </mml:mrow> </mml:math> .

Results of an extensive R&D program aiming at radiation hard, small pitch, 3D pixel sensors are reported. The CMS experiment is supporting this R&D in the scope of the Inner Tracker upgrade for the High Luminosity phase of the CERN Large Hadron Collider (HL-LHC). In the HL-LHC the Inner Tracker will have to withstand an integrated fluence up to 2.3×1016neq/cm2. A small number of 3D sensors were interconnected with the RD53A readout chip, which is the first prototype of 65 nm CMOS pixel readout chip designed for the HL-LHC pixel trackers. In this paper results obtained in beam tests before and after irradiation are reported. The irradiation of a single chip module was performed up to a maximum equivalent fluence of about 1×1016neq/cm2. The analysis of the collected data shows excellent performance: the spatial resolution in not irradiated sensors can reach about 3 to 5 μm, for inclined tracks, depending on the pixel pitch. The measured hit detection efficiencies are close to 99% measured both before and after the above mentioned irradiation fluence.

A bstract A search for new top quark interactions is performed within the framework of an effective field theory using the associated production of either one or two top quarks with a Z boson in multilepton final states. The data sample corresponds to an integrated luminosity of 138 fb − 1 of proton-proton collisions at $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 13 TeV collected by the CMS experiment at the LHC. Five dimension-six operators modifying the electroweak interactions of the top quark are considered. Novel machine-learning techniques are used to enhance the sensitivity to effects arising from these operators. Distributions used for the signal extraction are parameterized in terms of Wilson coefficients describing the interaction strengths of the operators. All five Wilson coefficients are simultaneously fit to data and 95% confidence level intervals are computed. All results are consistent with the SM expectations.

As part of a program to develop a silicon tracking device for the Superconducting Super Collider (SSC), radiation-hard CMOS transistors and p-i-n diodes have been exposed to the 800-MeV LAMPF (Los Alamos Meson Physics Facility) proton beam. The fluences accumulated in one week corresponded to the expected radiation levels of about ten SSC years. The leakage current constants for p-i-n diodes and threshold voltage shifts for CMOS transistors are determined under different biasing conditions. The results are presented and examined in detail.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

As part of a program to develop a silicon strip central tracking detector system for the Superconducting Super Collider (SSC), the effects of radiation damage in silicon detectors and their associated front-end readout electronics are being studied. The authors report on the results of neutron and proton irradiations at the Los Alamos National Laboratory and gamma -ray irradiations at UC Santa Cruz. Individual components on single-sided AC-coupled silicon strip detectors and on test structures were tested. Circuits fabricated in a radiation-hard CMOS process and individual transistors fabricated using dielectric isolation bipolar technology were also studied. Bulk damage to the silicon itself is seen as the limiting factor in the lifetime of a detector system. In particular, it is the acceptor site creation in the active volume of the silicon detector that will limit the lifetime to approximately 10 yr for the innermost detectors.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A Fabry-Perot cavity polarimeter, installed in 2003 at HERA for the second phase of its operation, is described. The cavity polarimeter was designed to measure the longitudinal polarisation of the HERA electron beam with high precision for each electron bunch spaced with a time interval of 96 ns. Within the cavity the laser intensity was routinely enhanced up to a few kW from its original value of 0.7 W in a stable and controllable way. By interacting such a high intensity laser beam with the HERA electron beam it is possible to measure its polarisation with a relative statistical precision of 2% per bunch per minute. Detailed systematic studies have also been performed resulting in a systematic uncertainty of 1%.

The Belle II experiment at the Super KEK B-factory (SuperKEKB) in

The development and first results are described of a silicon strip detector telescope for the HERA experiment H1 designed to measure the polar angle of deep inelastic scattered electrons at small Bjorken x and low momentum transfers Q2.

The parameters of the electroweak theory are determined in a combined electroweak and QCD analysis using all deep-inelastic $$e^+p$$ and $$e^-p$$ neutral current and charged current scattering cross sections published by the H1 Collaboration, including data with longitudinally polarised lepton beams. Various fits to Standard Model parameters in the on-shell scheme are performed. The mass of the W boson is determined as $$m_W=80.520\pm 0.115~\mathrm {GeV} $$ . The axial-vector and vector couplings of the light quarks to the Z boson are also determined. Both results improve the precision of previous H1 determinations based on HERA-I data by about a factor of two. Possible scale dependence of the weak coupling parameters in both neutral and charged current interactions beyond the Standard Model is also studied. All results are found to be consistent with the Standard Model expectations.

Signals of QCD instanton-induced processes are searched for in neutral current deep-inelastic scattering at the electron-proton collider HERA in the kinematic region defined by the Bjorken-scaling variable $$x > 10^{-3}$$ , the inelasticity $$0.2< y < 0.7$$ and the photon virtuality $$150< Q^2 < 15000$$ GeV $$^2$$ . The search is performed using H1 data corresponding to an integrated luminosity of 351 pb $$^{-1}$$ . No evidence for the production of QCD instanton-induced events is observed. Upper limits on the cross section for instanton-induced processes between 1.5 and 6 pb, at $$95\,\,\%$$ confidence level, are obtained depending on the kinematic domain in which instantons could be produced. Compared to earlier publications, the limits are improved by an order of magnitude and for the first time are challenging predictions.

Abstract We present the characterization of various components of the full custom bipolar process SHPi by Tektronix with respect to radiation hardness. The motivation of this work is to design a low-power, low-noise frontend with fast shaping for silicon microstrip detectors. We have tested BJTs ( npn of various size and a lateral pnp ), JFETs, Schottky diodes, implanted resistors and NiChrome resistors. The devices were irradiated to 60 Co dose of up to 5 Mrad in few steps, to fluence of 5.5∗10 13 n cm −2 of neutrons from a spallation source in few steps and to fluence of up to 1.1∗10 14 cm −2 of 650 MeV protons. It allows us to characterize the sensitivity of the devices on both ionization effects and displacement damage. We have measured the radiation effects on the dc parameters and characteristics of all components as well as on noise in npn BJTs of various size considered as candidates for the preamplifier input transistor. The most significant effect which we observe is the decrease of the current gain β in bipolar transistors for low emitter current densities. Both important noise sources, i.e. the shot noise of the collector current and the thermal noise of the base spread resistance are unaffected by irradiation.

AC-coupled silicon strip detectors were exposed to neutron fluences of 5·10 13 n/cm 2 and to Co 60 photon doses of 2.8 Mrad. No change in the value of the coupling capacitors was observed. Polysilicon resistor values increased by 15% and saturated after 200 krad photon dose. They were stable under neutron irradiation. Thee interstrip punchthrough threshold voltage increased from 4 to 13 V under photon irradiation. The accumulation of fixed charges in SiO 2 was measured using MOS capacitors and the photon-induced surface current generation velocity was determined with gated diodes.

Silicon strip detectors and test structures were exposed to neutron fluences up to Φ = 6.1 × 1014 n/cm2, using the ISIS neutron source at the Rutherford Appleton Laboratory (UK). In this paper we report some of our results concerning the effects of displacement damage, with a comparison of devices made of silicon of different resistivity. The various samples exposed showed a very similar dependence of the leakage current on the fluence received. We studied the change of effective doping concentration, and observed a behaviour suggesting the onset of type inversion at a fluence of ∼ 2.0 × 1013 n/cm2, a value which depends on the initial doping concentration. The linear increase of the depletion voltage for fluences higher than the inversion point could eventually determine the maximum fluence tolerable by silicon detectors.

A new pixel detector for the CMS experiment was built in order to cope with the instantaneous luminosities anticipated for the Phase~I Upgrade of the LHC. The new CMS pixel detector provides four-hit tracking with a reduced material budget as well as new cooling and powering schemes. A new front-end readout chip mitigates buffering and bandwidth limitations, and allows operation at low comparator thresholds. In this paper, comprehensive test beam studies are presented, which have been conducted to verify the design and to quantify the performance of the new detector assemblies in terms of tracking efficiency and spatial resolution. Under optimal conditions, the tracking efficiency is $99.95\pm0.05\,\%$, while the intrinsic spatial resolutions are $4.80\pm0.25\,\mu \mathrm{m}$ and $7.99\pm0.21\,\mu \mathrm{m}$ along the $100\,\mu \mathrm{m}$ and $150\,\mu \mathrm{m}$ pixel pitch, respectively. The findings are compared to a detailed Monte Carlo simulation of the pixel detector and good agreement is found.

With the LHC exceeding the nominal instantaneous luminosity, the current barrel pixel detector (BPIX) of the CMS experiment at CERN will reach its performance limits and undergo significant radiation damage. In order to improve detector performance in high luminosity conditions, the entire BPIX is replaced with an upgraded version containing an additional detection layer. Half of the modules comprising this additional layer are produced at DESY using fluxless and lead-free bumping and bonding techniques. Sequential solder-jetting technique is utilized to wet 40-μm SAC305 solder spheres on the silicon-sensor pads with electroless Ni, Pd and immersion Au (ENEPIG) under-bump metallization (UBM). The bumped sensors are flip-chip assembled with readout chips (ROCs) and then reflowed using a flux-less bonding facility. The challenges for jetting low solder volume have been analyzed and will be presented in this paper. An average speed of 3.4 balls per second is obtained to jet about 67 thousand solder balls on a single chip. On average, 7 modules have been produced per week. The bump-bond quality is evaluated in terms of electrical and mechanical properties. The peak-bump resistance is about 17.5 mΩ. The cross-section study revealed different types of intermetallic compounds (IMC) as a result of interfacial reactions between UBM and solder material. The effect of crystalline phases on the mechanical properties of the joint is discussed. The mean shear strength per bump after the final module reflow is about 16 cN. The results and sources of yield loss of module production are reported. The achieved yield is 95%.

The topic of the paper is the position reconstruction from signals of segmented detectors. With the help of a simple simulation, it is shown that the position reconstruction using the centre-of-gravity method is strongly biased, if the width of the charge (or e.g. light) distribution at the electrodes (or photo detectors) is less than the read-out pitch. A method is proposed which removes this bias for events with signals in two or more read-out channels and thereby improves the position resolution. The method also provides an estimate of the position–response function for every event. Examples are given for which its width as a function of the reconstructed position varies by as much as an order of magnitude. A fast Monte Carlo program is described which simulates the signals from a silicon pixel detector traversed by charged particles under different angles, and the results obtained with the proposed reconstruction method and with the centre-of-gravity method are compared. The simulation includes the local energy-loss fluctuations, the position-dependent electric field, the diffusion of the charge carriers, the electronics noise and charge thresholds for clustering, A comparison to test-beam-data is used to validate the simulation.

The fast and slow control of the central silicon tracker in H1 is performed by means of an ASIC decoder chip having four digital input lines. These control signals as well as the analog hit signals are transmitted to and from the detector through 34 m of optical fibers, which are composed of three connectable multifiber cables.

In this technical note we briefly present the analysis of the HERA polarimeters (transversal and longitudinal) as of summer 2011. We present the final reanalysis of the TPOL data, and discuss the systematic uncertainties. A procedure to combine and average LPOL and TPOL data is presented.

Abstract Prototype double sided silicon strip detectors for the H1 vertex detector have been fabricated. The design uses integrated coupling capacitors on both sides and a second metal layer with readout lines on the n-side. Measurements of leakage currents, sheet resistances, metal line quality and contact reliability all show satisfactory results. A multi-guard structure improves the high-voltage and long-term stability of the detectors. The accumulation layer channel resistors on the n-side showed dramatic radiation effects after 60Co doses of 100 krad and an improved design with a metal gate electrode is demonstrated. Interstrip capacitances have been measured systematically on test structures with various geometries. The capacitance due to the second metal layer on the n-side has been measured for a 2 μm SiO2 and a 6 μm polyimide dielectric. Up to now, integrated coupling capacitors could not be fabricated with sufficiently low defect rates.

A study of 3D pixel sensors of cell size 50 {\mu}m x 50 {\mu}m fabricated at IMB-CNM using double-sided n-on-p 3D technology is presented. Sensors were bump-bonded to the ROC4SENS readout chip. For the first time in such a small-pitch hybrid assembly, the sensor response to ionizing radiation in a test beam of 5.6 GeV electrons was studied. Results for non-irradiated sensors are presented, including efficiency, charge sharing, signal-to-noise, and resolution for different incidence angles.

Measurements of $$D^{*}(2010)$$ meson production in diffractive deep inelastic scattering $$(5<Q^{2}<100\,\mathrm{GeV}^{2})$$ are presented which are based on HERA data recorded at a centre-of-mass energy $$\sqrt{s} = 319\,\mathrm{GeV}$$ with an integrated luminosity of 287 pb $$^{-1}$$ . The reaction $$ep \rightarrow eXY$$ is studied, where the system X, containing at least one $$D^{*}(2010)$$ meson, is separated from a leading low-mass proton dissociative system Y by a large rapidity gap. The kinematics of $$D^{*}$$ candidates are reconstructed in the $$D^{*}\rightarrow K \pi \pi $$ decay channel. The measured cross sections compare favourably with next-to-leading order QCD predictions, where charm quarks are produced via boson-gluon fusion. The charm quarks are then independently fragmented to the $$D^{*}$$ mesons. The calculations rely on the collinear factorisation theorem and are based on diffractive parton densities previously obtained by H1 from fits to inclusive diffractive cross sections. The data are further used to determine the diffractive to inclusive $$D^{*}$$ production ratio in deep inelastic scattering.

The authors present radiation hardness measurements of both small-scale bipolar test structures and full amplifier-comparator circuits built in the Tektronix SHPi process. BJTs (bipolar junction transistors (npm of various sizes and a lateral pnp), JFETs (junction field effect transistors), diodes, and resistors have been irradiated to /sup 60/Co doses of up to 5 Mrad and to fluences of up to 1.1*10/sup 14/ cm/sup -2/ of 650 MeV protons. Radiation effects on transistor noise and current gain, the value of the pinch-off voltage and output resistance of the JFET, leakage of diodes, and resistor values are discussed. A full 64-channel amplifier-comparator circuit was exposed to 3.5 Mrad of gammas, and changes in gain and noise were measured. It is concluded that the Tektronix SHPi process appears to offer sufficient radiation hardness for the design of fast, low-power amplifier circuits for the Superconducting Super Collider.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The H1 experiment consists of some half million electronics channels in an environment of 96 ns bunch crossings at the HERA e-p collider at DESY, Hamburg. The data acquisition system built to read out the silicon tracking devices is described. Several technologies are employed in integrating ASIC devices, large numbers of FADCs, fibre-optic interconnections and the latest commercial microprocessor architectures in modular bus standards such as VMEbus and the recent PCI definition. The experiences gained in system development are highlighted, which provide significant pointers to the problems posed by the next generation of hadron colliders.

This is a status report on the design of a large silicon tracking detector for the superconducting supercollider (SSC). We present our design, the principles on which it is based and initial work on the mechanical support structure for the detectors.

The H1 detector at HERA at DESY presently undergoes a major upgrade. In this context silicon strip detectors have been installed at the beginning of 1995. The high bunch crossing frequency of HERA (10.4 MHz) demands a novel readout architecture which includes pipelining, signal processing and data reduction at a very early stage. The front end readout is hierarchically organized. The detector elements are read out by the APC chip which contains an analog pipeline and performs first background subtraction. Up to five readout chips are controlled by a Decoder Chip. The readout processor module (OnSiRoC) operates the detectors, controls the Decoder Chips and performs a first level data reduction. The paper describes the readout architecture of the H1 silicon detectors and performance data of the complete readout chain.

Abstract The determination of the strong coupling constant $$\alpha _{\mathrm{s}} (m_{\mathrm{Z}})$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>α</mml:mi> <mml:mi>s</mml:mi> </mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Z</mml:mi> </mml:msub> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> from H1 inclusive and dijet cross section data [1] exploits perturbative QCD predictions in next-to-next-to-leading order (NNLO) [2–4]. An implementation error in the NNLO predictions was found [4] which changes the numerical values of the predictions and the resulting values of the fits. Using the corrected NNLO predictions together with inclusive jet and dijet data, the strong coupling constant is determined to be $$\alpha _{\mathrm{s}} (m_{\mathrm{Z}}) =0.1166\,(19)_{\mathrm{exp}}\,(24)_{\mathrm{th}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>α</mml:mi> <mml:mi>s</mml:mi> </mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Z</mml:mi> </mml:msub> <mml:mo>)</mml:mo> </mml:mrow> <mml:mo>=</mml:mo> <mml:mn>0.1166</mml:mn> <mml:mspace /> <mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>19</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mi>exp</mml:mi> </mml:msub> <mml:mspace /> <mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>24</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mi>th</mml:mi> </mml:msub> </mml:mrow> </mml:math> . Complementarily, $$\alpha _{\mathrm{s}} (m_{\mathrm{Z}})$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>α</mml:mi> <mml:mi>s</mml:mi> </mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Z</mml:mi> </mml:msub> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value $$\alpha _{\mathrm{s}} (m_{\mathrm{Z}}) =0.1147\,(25)_{\mathrm{tot}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>α</mml:mi> <mml:mi>s</mml:mi> </mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Z</mml:mi> </mml:msub> <mml:mo>)</mml:mo> </mml:mrow> <mml:mo>=</mml:mo> <mml:mn>0.1147</mml:mn> <mml:mspace /> <mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>25</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mi>tot</mml:mi> </mml:msub> </mml:mrow> </mml:math> obtained is consistent with the determination from jet data alone. Corrected figures and numerical results are provided and the discussion is adapted accordingly.

Summary form only. A silicon vertex detector for tagging secondary vertices from charm decays has been proposed for the H1 experiment. It uses two layers of double-sided silicon strip detectors in a barrel geometry. A beam pipe radius of 35 mm with a horizontal offset of 10 mm from the beam axis is possible at HERA with an upgrade of existing synchrotron radiation masks. Prototypes of the front-end electronics in 2- mu m CMOS technology have been successfully tested. The preamplifier has a risetime of 100 ns and an equivalent noise charge of 1400 electrons at 24 pF load while operating with 0.28 mW power per channel. The analog signals are stored in a capacitor pipeline of 32 cells per channel to allow for the level trigger decision time. One channel with preamplifier and pipeline has a width of 44 mu m on the chip. The CMOS process is not radiation-hardened but the prototype circuits were functional up to doses of 150 krad, albeit with increased power and noise.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Summary form only. A silicon vertex detector has been proposed for the H1 experiment at HERA. The bunch crossing interval of 96 ns and the level 1 trigger decision time of 2.2 mu s requires a multievent pipeline integrated to the front-end electronics. The design uses 32 switched capacitors on each channel to store the output voltage of the preamplifier. The chip architecture uses the preamplifier to read back any buffer selected by a level 1 trigger before the analog signals are read out serially. Prototypes have been produced in 2 mu m CMOS technology. One channel has a width of 44 mu m and a length of 2.4 mm. The preamplifier has a single gain stage with active load which offers minimal power dissipation of 280 mu W per channel for an open-loop gain of 80. The radiation hardness of the CMOS process was tested in a Co/sup 60/ source, and the chips were found to be functional up to a dose of 150 krad, albeit with increased power (30%) and increased noise slope versus capacitance (100%). Radiation-induced threshold voltage shifts are compensated internally by constant current biasing for the preamplifier.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

More than 100 people participated in a discussion session at the DIS08 workshop on the topic What HERA may provide. A summary of the discussion with a structured outlook and list of desirable measurements and theory calculations is given.

Pixelated silicon detectors are state-of-the-art technology to achieve precise tracking and vertexing at collider experiments, designed to accurately measure the hit position of incoming particles in high rate and radiation environments. The detector requirements become extremely demanding for operation at the High-Luminosity LHC, where up to 200 interactions will overlap in the same bunch crossing on top of the process of interest. Additionally, fluences up to 2.3 10^16 cm^-2 1 MeV neutron equivalent at 3.0 cm distance from the beam are expected for an integrated luminosity of 3000 fb^-1. In the last decades, the pixel pitch has constantly been reduced to cope with the experiment's needs of achieving higher position resolution and maintaining low pixel occupancy per channel. The spatial resolution improves with a decreased pixel size but it degrades with radiation damage. Therefore, prototype sensor modules for the upgrade of the experiments at the HL-LHC need to be tested after being irradiated. This paper describes position resolution measurements on planar prototype sensors with 100x25 um^2 pixels for the CMS Phase-2 Upgrade. It reviews the dependence of the position resolution on the relative inclination angle between the incoming particle trajectory and the sensor, the charge threshold applied by the readout chip, and the bias voltage. A precision setup with three parallel planes of sensors has been used to investigate the performance of sensors irradiated to fluences up to F_eq = 3.6 10^15 cm-2. The measurements were performed with a 5 GeV electron beam. A spatial resolution of 3.2 +\- 0.1 um is found for non-irradiated sensors, at the optimal angle for charge sharing. The resolution is 5.0 +/- 0.2 um for a proton-irradiated sensor at F_eq = 2.1 10^15 cm-2 and a neutron-irradiated sensor at F_eq = 3.6 10^15 cm^-2.

More than 100 people participated in a discussion session at the DIS08 workshop on the topic What HERA may provide. A summary of the discussion with a structured outlook and list of desirable measurements and theory calculations is given.

We describe the status of the front-end electronics for silicon microstrip detectors in the Leading Proton Spectrometer (LPS) in ZEUS at HERA. We present new data on the radiation hardness of dielectric isolated bipolar transistors and of logic gates from a recent radiation-hard CMOS test run.

The H1 detector at the electron proton collider HERA at DESY undergoes at present a major upgrade program. In this context a Silicon Tracking Detector System is under construction. This system consist of a cylindrical vertex type detector around the interaction point (CST) and disk-shaped silicon detectors of different types in the backward (i.e. electron) direction (BST). The readout for the strip detectors is based on a novel front-end readout chip (APC) and a new readout processor (onSiRoC). The readout is pipelined in order to cope with the bunch crossing frequency of 10.6 MHz of HERA. The readout has many features to compress data at the earliest stage. The implementation into the H1 data acquisition is organized using the VMEbus standards and exploiting existing H1 software packages as much as possible.

Pixelated silicon detectors are state-of-the-art technology to achieve precise tracking and vertexing at collider experiments, designed to accurately measure the hit position of incoming particles in high rate and radiation environments. The detector requirements become extremely demanding for operation at the High-Luminosity LHC, where up to 200 interactions will overlap in the same bunch crossing on top of the process of interest. Additionally, fluences up to 2.3 10^16 cm^-2 1 MeV neutron equivalent at 3.0 cm distance from the beam are expected for an integrated luminosity of 3000 fb^-1. In the last decades, the pixel pitch has constantly been reduced to cope with the experiment's needs of achieving higher position resolution and maintaining low pixel occupancy per channel. The spatial resolution improves with a decreased pixel size but it degrades with radiation damage. Therefore, prototype sensor modules for the upgrade of the experiments at the HL-LHC need to be tested after being irradiated. This paper describes position resolution measurements on planar prototype sensors with 100x25 um^2 pixels for the CMS Phase-2 Upgrade. It reviews the dependence of the position resolution on the relative inclination angle between the incoming particle trajectory and the sensor, the charge threshold applied by the readout chip, and the bias voltage. A precision setup with three parallel planes of sensors has been used to investigate the performance of sensors irradiated to fluences up to F_eq = 3.6 10^15 cm-2. The measurements were performed with a 5 GeV electron beam. A spatial resolution of 3.2 +\- 0.1 um is found for non-irradiated sensors, at the optimal angle for charge sharing. The resolution is 5.0 +/- 0.2 um for a proton-irradiated sensor at F_eq = 2.1 10^15 cm-2 and a neutron-irradiated sensor at F_eq = 3.6 10^15 cm^-2.

Abstract The measurement of the jet cross sections by the H1 collaboration had been compared to various predictions including the next-to-next-to-leading order (NNLO) QCD calculations which are corrected in this erratum for an implementation error in one of the components of the NNLO calculations. The jet data and the other predictions remain unchanged. Eight figures, one table and conclusions are adapted accordingly, exhibiting even better agreement between the corrected NNLO predictions and the jet data.

The first measurement of lepton-jet momentum imbalance and azimuthal correlation in lepton-proton scattering at high momentum transfer is presented. These data, taken with the H1 detector at HERA, are corrected for detector effects using an unbinned machine learning algorithm OmniFold, which considers eight observables simultaneously in this first application. The unfolded cross sections are compared to calculations performed within the context of collinear or transverse-momentum-dependent (TMD) factorization in Quantum Chromodynamics (QCD) as well as Monte Carlo event generators. The measurement probes a wide range of QCD phenomena, including TMD parton distribution functions and their evolution with energy in so far unexplored kinematic regions.

Summary form only given, as follows. As part of a program to develop silicon central tracking systems for the next generation of high-energy, high-luminosity accelerators such as the Superconducting Super Collider and the Relativistic Heavy Ion Collider, the effects of radiation damage in silicon detectors are being studied in detail. Results on neutron and proton irradiations at Los Alamos National Laboratory and gamma ray irradiations at UC Santa Cruz have been obtained. The devices being tested include both single-sided and double-sided silicon strip detectors, as well as test structures. Results of measurements of leakage current, acceptor state creation, charge trapping, pulse shapes, and changes in interstrip resistance as a function dose and operating temperature have been obtained.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The readout system of the H1 Central and Backward Silicon Tracker detectors is processing the data of about 120 000 analog readout channels. The strip data are digitized and processed by VMEbus Readout Processor Modules equipped with a local PCI bus and a 96 MHz PowerPC 604 processor. The processor performs a cluster search and reduces the raw data size by an average factor of 40. It also updates the pedestals and noise variances periodically. Events can be processed at up to 100 Hz, well matching the second level trigger rates.

As part of a program to develop a silicon strip central tracking detector system for the Superconducting Super Collider (SSC) we are studying the effects of radiation damage in silicon detectors and their associated front-end readout electronics. We report on the results of neutron and proton irradiations at the Los Alamos National Laboratory (LANL) and {gamma}-ray irradiations at UC Santa Cruz (UCSC). Individual components on single-sided AC-coupled silicon strip detectors and on test structures were tested. Circuits fabricated in a radiation hard CMOS process and individual transistors fabricated using dielectric isolation bipolar technology were also studied. Results indicate that a silicon strip tracking detector system should have a lifetime of at least one decade at the SSC. 17 refs., 17 figs.