Publications (286)750.85 Total impact

Article: Combination of differential D∗± crosssection measurements in deepinelastic ep scattering at HERA
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ABSTRACT: H1 and ZEUS have published singledifferential cross sections for inclusive D∗±meson production in deepinelastic ep scattering at HERA from their respective final data sets. These cross sections are combined in the common visible phasespace region of photon virtuality Q2> 5 GeV2, electron inelasticity 0.02 < y < 0.7 and the D∗± meson’s transverse momentum pT(D∗) > 1.5 GeV and pseudorapidity η(D∗) < 1.5. The combination procedure takes into account all correlations, yielding significantly reduced experimental uncertainties. Doubledifferential cross sections d2σ/dQ2dy are combined with earlier D∗± data, extending the kinematic range down to Q2> 1.5 GeV2. Perturbative nexttoleadingorder QCD predictions are compared to the results.Journal of High Energy Physics 09/2015; 2015(9). DOI:10.1007/JHEP09(2015)149 · 6.11 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: The cross section of the diffractive process e+p → e+Xp is measured at a centreofmass 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 Q2< 2 GeV2 and in deepinelastic scattering with 4 GeV2< Q2< 80 GeV2. The results are compared to next toleading order QCD calculations based on diffractive parton distribution functions as extracted from measurements of inclusive cross sections in diffractive deepinelastic scattering.Journal of High Energy Physics 05/2015; 2015(5). DOI:10.1007/JHEP05(2015)056 · 6.11 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: Inclusive jet, dijet and trijet differential cross sections are measured in neutral current deepinelastic scattering for exchanged boson virtualities using the H1 detector at HERA. The data were taken in the years 2003 to 2007 and correspond to an integrated luminosity of. Double differential Jet cross sections are obtained using a regularised unfolding procedure. They are presented as a function of and the transverse momentum of the jet, and as a function of and the proton’s longitudinal momentum fraction, carried by the parton participating in the hard interaction. In addition normalised double differential jet cross sections are measured as the ratio of the jet cross sections to the inclusive neutral current cross sections in the respective bins of the jet measurements. Compared to earlier work, the measurements benefit from an improved reconstruction and calibration of the hadronic final state. The cross sections are compared to perturbative QCD calculations in nexttoleading order and are used to determine the running coupling and the value of the strong coupling constant as.European Physical Journal C 02/2015; 75(2). DOI:10.1140/epjc/s1005201432236 · 5.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: 160 pages, 83 figures ; See paper for full list of authors  [Show abstract] [Hide abstract]
ABSTRACT: A search for excited electrons is performed using the full e±p data sample collected by the H1 experiment at HERA, corresponding to a total luminosity of 475 pb−1. The electroweak decays of excited electrons e∗→eγ, e∗→eZ and e∗→νW with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for excited electron production is found. Mass dependent exclusion limits on e∗ production cross sections and on the ratio f/Λ of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited electron searches. The e∗ production via contact interactions is also addressed for the first time in ep collisions.Physics Letters B 09/2013; 666(2):131139. DOI:10.1016/j.physletb.2008.07.014 · 6.13 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: A search for scalar and vector leptoquarks coupling to first generation fermions is performed using the e+p and e−p scattering data collected by the H1 experiment between 1994 and 2000. The data correspond to a total integrated luminosity of 117 pb−1. No evidence for the direct or indirect production of such particles is found in data samples with a large transverse momentum final state electron or with large missing transverse momentum. Constraints on leptoquark models are established. For leptoquark couplings of electromagnetic strength, leptoquarks with masses up to 275–325 GeV are ruled out at 95% confidence level. These limits improve and supercede earlier H1 limits based on subsamples of the data used here.Physics Letters B 09/2013; 629(1):919. DOI:10.1016/j.physletb.2005.09.048 · 6.13 Impact Factor 
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ABSTRACT: Cross sections for elastic and protondissociative photoproduction of J/psi mesons are measured with the H1 detector in positronproton collisions at HERA. The data were collected at $ep$ centreofmass energies sqrt{s} approx 318 GeV and sqrt{s} approx 225 GeV, corresponding to integrated luminosities of L = 130 pb^{1} and L = 10.8 pb^{1}, respectively. The cross sections are measured as a function of the photonproton centreofmass energy in the range 25< Wgp < 110 GeV. Differential cross sections $\mathrm{d}\sigma / \mathrm{d}t$, where $t$ is the squared fourmomentum transfer at the proton vertex, are measured in the range $t < 1.2 \, \gevsq$ for the elastic process and $t < 8 \, \gevsq$ for proton dissociation. The results are compared to other measurements. The $\Wgp$ and $t$dependences are parametrised using phenomenological fits.European Physical Journal C 04/2013; 73:2466. DOI:10.1140/epjc/s100520132466y · 5.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: Charged particle production in deepinelastic ep scattering is measured with the H1 detector at HERA. The kinematic range of the analysis covers low photon virtualities, 5 < Q^2 < 100 GeV^2, and small values of Bjorkenx, 10^{4} < x < 10^{2}. The analysis is performed in the hadronic centreofmass system. The charged particle densities are measured as a function of pseudorapidity (eta^*) and transverse momentum (p_T^*) in the range 0< \eta^* < 5 and 0< p_T^* < 10$ GeV differentially in x and Q^2. The data are compared to predictions from different Monte Carlo generators implementing various options for hadronisation and parton evolutions.European Physical Journal C 02/2013; 73:2406. DOI:10.1140/epjc/s100520132406x · 5.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: Measurements of open charm production cross sections in deepinelastic ep scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections \(\sigma_{\rm red}^{c\bar{c}}\) for charm production are obtained in the kinematic range of photon virtuality 2.5≤Q 2≤2000 GeV2 and Bjorken scaling variable 3⋅10−5≤x≤5⋅10−2. The combination method accounts for the correlations of the systematic uncertainties among the different data sets. The combined charm data together with the combined inclusive deepinelastic scattering cross sections from HERA are used as input for a detailed NLO QCD analysis to study the influence of different heavy flavour schemes on the parton distribution functions. The optimal values of the charm mass as a parameter in these different schemes are obtained. The implications on the NLO predictions for W ± and Z production cross sections at the LHC are investigated. Using the fixed flavour number scheme, the running mass of the charm quark is determined.European Physical Journal C 02/2013; 73:2311. DOI:10.1140/epjc/s1005201323113 · 5.08 Impact Factor 
Dataset: desy06110

Dataset: desy06110
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ABSTRACT: Inclusive production of D ∗ mesons in deepinelastic ep scattering at HERA is studied in the range 5<Q 2<100 GeV2 of the photon virtuality and 0.02<y<0.7 of the inelasticity of the scattering process. The observed phase space for the D ∗ meson is p T (D ∗)>1.25 GeV and η(D ∗)<1.8. The data sample corresponds to an integrated luminosity of 348 pb−1 collected with the H1 detector. Single and double differential cross sections are measured and the charm contribution \({F_{2}^{c\bar{c}}}\) to the proton structure function F 2 is determined. The results are compared to perturbative QCD predictions at nexttoleading order implementing different schemes for the charm mass treatment and with Monte Carlo models based on leading order matrix elements with parton showers.European Physical Journal C 12/2012; 72(12). DOI:10.1140/epjc/s1005201222522 · 5.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: A combination of the inclusive diffractive cross section measurements made by the H1 and ZEUS Collaborations at HERA is presented. The analysis uses samples of diffractive deep inelastic ep scattering data at a centreofmass energy sqrt(s) = 318 GeV where leading protons are detected by dedicated spectrometers. Correlations of systematic uncertainties are taken into account, resulting in an improved precision of the cross section measurement which reaches 6% for the most precise points. The combined data cover the range 2.5 < Q2 < 200 GeV2 in photon virtuality, 0.00035 < xIP < 0.09 in proton fractional momentum loss, 0.09 < t < 0.55 GeV2 in squared fourmomentum transfer at the proton vertex and 0.0018 < beta < 0.816 in beta = x/xIP, where x is the Bjorken scaling variable.European Physical Journal C 07/2012; 72:2175. DOI:10.1140/epjc/s100520122175y · 5.08 Impact Factor 
Article: Measurement of beauty and charm photoproduction using semimuonic decays in dijet events at HERA
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ABSTRACT: Measurements of cross sections for beauty and charm events with dijets and a muon in the photoproduction regime at HERA are presented. The data were collected with the H1 detector and correspond to an integrated luminosity of 179 pb−1. Events with dijets of transverse momentum \(P_{T}^{\mathrm{jet}1}> 7\ \mbox{GeV}\) and \(P_{T}^{\mathrm{jet}2}> 6\ \mbox{GeV}\) in the pseudorapidity range −1.5<η jet<2.5 in the laboratory frame are selected in the kinematic region of photon virtuality Q 2<2.5 GeV2 and inelasticity 0.2<y<0.8. One of the two selected jets must be associated to a muon with \(P_{T}^{\mu} > 2.5\ \mbox{GeV}\) in the pseudorapidity range −1.3<η μ <1.5. The fractions of beauty and charm events are determined using the impact parameters of the muon tracks with respect to the primary vertex and their transverse momentum relative to the axis of the associated jet. Both variables are reconstructed using the H1 vertex detector. The measurements are in agreement with QCD predictions at leading and nexttoleading order.European Physical Journal C 07/2012; 72(6). DOI:10.1140/epjc/s1005201220475 · 5.08 Impact Factor 
Article: Inclusive Deep Inelastic Scattering at High Q2 with LongitudinallyPolarised Lepton Beams at HERA
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ABSTRACT: Inclusive e ± p single and double differential cross sections for neutral and charged current deep inelastic scattering processes are measured with the H1 detector at HERA. The data were taken at a centreofmass energy of \( \sqrt {s} = {319} \) GeV with a total integrated luminosity of 333.7 pb−1 shared between two lepton beam charges and two longitudinal lepton polarisation modes. The differential cross sections are measured in the range of negative fourmomentum transfer squared, Q 2, between 60 and 50 000 GeV2, and Bjorken x between 0.0008 and 0.65. The measurements are combined with earlier published unpolarised H1 data to improve statistical precision and used to determine the structure function \( xF_{3}^{{\gamma Z}} \). Ameasurementoftheneutralcurrentparityviolating structure function \( F_{2}^{{\gamma Z}} \) is presented for the first time. The polarisation dependence of the charged current total cross section is also measured. The new measurements are well described by a nexttoleading order QCD fit based on all published H1 inclusive cross section data which are used to extract the parton distribution functions of the proton.Journal of High Energy Physics 06/2012; 1209:061. DOI:10.1007/JHEP09(2012)061 · 6.11 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: The cross section for ep > e b\bar{b} X in photoproduction is measured with the H1 detector at the epcollider HERA. The decay channel b\bar{b} > ee X' is selected by identifying the semielectronic decays of the bquarks. The total production cross section is measured in the kinematic range given by the photon virtuality Q^2 <= 1 GeV^2, the inelasticity 0.05 <= y <= 0.65 and the pseudorapidity of the bquarks eta(b),eta(\bar{b}) <= 2. The differential production cross section is measured as a function of the average transverse momentum of the beauty quarks <P_T(b)> down to the threshold. The results are compared to nexttoleadingorder QCD predictions.European Physical Journal C 06/2012; 72(10). DOI:10.1140/epjc/s1005201221481 · 5.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: A measurement of the integrated luminosity at the ep collider HERA is presented, exploiting the elastic QED Compton process ep \rightarrow ep. The electron and the photon are detected in the backward calorimeter of the H1 experiment. The integrated luminosity of the data recorded in 2003 to 2007 is determined with a precision of 2.3%. The measurement is found to be compatible with the corresponding result obtained using the BetheHeitler process.European Physical Journal C 05/2012; 72(10). DOI:10.1140/epjc/s1005201221632 · 5.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: The inclusive photoproduction of D ∗ mesons and of D ∗tagged dijets is investigated with the H1 detector at the ep collider HERA. The kinematic region covers small photon virtualities Q 2<2 GeV2 and photon–proton centreofmass energies of 100<W γp <285 GeV. Inclusive D ∗ meson differential cross sections are measured for central rapidities η(D ∗)<1.5 and transverse momenta p T (D ∗)>1.8 GeV. The heavy quark production process is further investigated in events with at least two jets with transverse momentum p T (jet)>3.5 GeV each, one containing the D ∗ meson. Differential cross sections for D ∗tagged dijet production and for correlations between the jets are measured in the range η(D ∗)<1.5 and p T (D ∗)>2.1 GeV. The results are compared with predictions from Monte Carlo simulations and nexttoleading order perturbative QCD calculations.European Physical Journal C 05/2012; 72(5). DOI:10.1140/epjc/s1005201219950 · 5.08 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: The cross section of diffractive deepinelastic scattering ep→eXp is measured, where the system X contains at least two jets and the leading final state proton is detected in the H1 Forward Proton Spectrometer. The measurement is performed for fractional proton longitudinal momentum loss x ℙ<0.1 and covers the range 0.1<t<0.7 GeV2 in squared fourmomentum transfer at the proton vertex and 4<Q 2<110 GeV2 in photon virtuality. The differential cross sections extrapolated to t<1 GeV2 are in agreement with nexttoleading order QCD predictions based on diffractive parton distribution functions extracted from measurements of inclusive and dijet cross sections in diffractive deepinelastic scattering. The data are also compared with leading order Monte Carlo models.European Physical Journal C 04/2012; 72(4). DOI:10.1140/epjc/s1005201219709 · 5.08 Impact Factor
Publication Stats
3k  Citations  
750.85  Total Impact Points  
Top Journals
Institutions

19992013

Joint Institute for Nuclear Research
 Bogoliubov Laboratory of Theoretical Physics
Dubno, Moskovskaya, Russia


20002009

University of Hamburg
 Institut für Experimentalphysik
Hamburg, Hamburg, Germany 
HumboldtUniversität zu Berlin
 Department of Physics
Berlín, Berlin, Germany


20032005

University of Birmingham
 School of Physics and Astronomy
Birmingham, ENG, United Kingdom
