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Elastic J/ψ production at HERA
(2006)The European Physical Journal CCross sections for elastic production of J/ψ mesons in photoproduction and electroproduction are measured in electron proton collisions at HERA using an integrated luminosity of 55 pb-1. Results are presented for photon virtualities Q2 up to 80 GeV2. The dependence on the photon-proton centre of mass energy Wγp is analysed in the range 40≤Wγp≤305 GeV in photoproduction and 40≤Wγp≤160 GeV in electroproduction. The Wγp dependences of the ...Journal Article -
Measurement of event shape variables in deep-inelastic scattering at HERA
(2006)The European Physical Journal CDeep-inelastic ep scattering data taken with the H1 detector at HERA and corresponding to an integrated luminosity of 106 pb-1 are used to study the differential distributions of event shape variables. These include thrust, jet broadening, jet mass and the C-parameter. The four-momentum transfer Q is taken to be the relevant energy scale and ranges between 14 GeV and 200 GeV. The event shape distributions are compared with perturbative ...Journal Article -
Diffractive deep-inelastic scattering with a leading proton at HERA
(2006)The European Physical Journal CThe cross section for the diffractive deep-inelastic scattering process ep→eXp is measured, with the leading final state proton detected in the H1 Forward Proton Spectrometer. The data analysed cover the range xIP<0.1 in fractional proton longitudinal momentum loss, 0.08<|t|<0.5 GeV-2 in squared four-momentum transfer at the proton vertex, 2<Q2<50 GeV2 in photon virtuality and 0.004<β=x/xIP<1, where x is the Bjorken scaling variable. For ...Journal Article -
Measurement of charm and beauty dijet cross sections in photoproduction at HERA using the H1 vertex detector
(2006)The European Physical Journal CA measurement of charm and beauty dijet photoproduction cross sections at the ep collider HERA is presented. Events are selected with two or more jets of transverse momentum pt jet1(2)>11(8) GeV in the central range of pseudo-rapidity -0.9<ηjet1(2)<1.3. The fractions of events containing charm and beauty quarks are determined using a method based on the impact parameter, in the transverse plane, of tracks to the primary vertex, as measured ...Journal Article -
Deeply virtual Compton scattering and its beam charge asymmetry in e±p collisions at HERA
(2009)Physics Letters BA measurement of elastic deeply virtual Compton scattering γ * p → γ p using e + p and e - p collision data recorded with the H1 detector at HERA is presented. The analysed data sample corresponds to an integrated luminosity of 306 pb -1, almost equally shared between both beam charges. The cross section is measured as a function of the virtuality Q 2 of the exchanged photon and the centre-of-mass energy W of the γ * p system in the ...Journal Article -
Search for baryonic resonances decaying to Ξπ in deep-inelastic scattering at HERA
(2007)The European Physical Journal CA search for narrow baryonic resonances decaying into Ξ-π- or Ξ-π+ and their antiparticles is carried out with the H1 detector using deep inelastic scattering events at HERA in the range of negative photon four-momentum transfer squared 2 < Q2 < 100 GeV2. No signal is observed for a new baryonic state in the mass range 1600–2300 MeV in either the doubly charged or the neutral decay channels. The known Ξ(1530)0 is observed through its decay ...Journal Article -
A precision measurement of the inclusive ep scattering cross section at HERA
(2009)The European Physical Journal CA measurement of the inclusive deep inelastic neutral current e + p scattering cross section is reported in the region of four-momentum transfer squared, 12 GeV2≤Q 2≤150 GeV2, and Bjorken x, 2×10−4≤x≤0.1. The results are based on data collected by the H1 Collaboration at the ep collider HERA at positron and proton beam energies of E e =27.6 GeV and E p =920 GeV, respectively. The data are combined with previously published data, taken at ...Journal Article -
Inclusive D*± meson and associated dijet production in deep-inelastic scattering at HERA
(2007)The European Physical Journal CInclusive D*± production is measured in deep-inelastic ep scattering at HERA with the H1 detector. In addition, the production of dijets in events with a D*± meson is investigated. The analysis covers values of photon virtuality 2 ≤ Q2 ≤ 100 GeV2 and of inelasticity 0.05≤y≤0.7. Differential cross sections are measured as a function of Q2 and x and of various D*± meson and jet observables. Within the experimental and theoretical uncertainties ...Journal Article -
Tests of QCD factorisation in the diffractive production of dijets in deep-inelastic scattering and photoproduction at HERA
(2007)The European Physical Journal CMeasurements are presented of differential dijet cross sections in diffractive photoproduction (Q2<0.01 GeV2) and deep-inelastic scattering processes (DIS, 4<Q2<80 GeV2). The event topology is given by ep→eXY, in which the system X, containing at least two jets, is separated from a leading low-mass baryonic system Y by a large rapidity gap. The dijet cross sections are compared with NLO QCD predictions based on diffractive parton densities ...Journal Article -
Events with isolated leptons and missing transverse momentum and measurement of W production at HERA
(2009)The European Physical Journal CEvents with high energy isolated electrons, muons or tau leptons and missing transverse momentum are studied using the full e ± p data sample collected by the H1 experiment at HERA, corresponding to an integrated luminosity of 474 pb−1. Within the Standard Model, events with isolated leptons and missing transverse momentum mainly originate from the production of single W bosons. The total single W boson production cross section is measured ...Journal Article