Studies of DVCS and photoproduction of photons at high t with the H1 Detector
نویسنده
چکیده
The diffractive scattering of photon off proton γp→ γY (where Y denotes the proton dissociative system or the elastically scattered proton) is measured in two different kinematic regimes at high energy with the H1 detector at HERA. i) the process is studied for the first time at large transverse photon momentum pγt > 2 GeV in photoproduction regime (Q 2 < 0.01 GeV) and photon-proton c.m.s. energy 175 < W < 247 GeV. The cross section is measured differentially in t and in xIP . The measurement is compared to a LL BFKL prediction of QCD. ii) in electroproduction, the Deeply Virtual Compton Scattering (DVCS) γ∗p → γp cross section has been measured more precisely and in an extended kinematic domain: at photon virtualities 4 < Q < 80 GeV and 30 < W < 140 GeV. The measurement is compared to NLO QCD calculations using the DGLAP approximation and to Colour Dipole model predictions. PACS. 12.38.Qk Experimental tests – 12.38.Aw General properties of QCD
منابع مشابه
ar X iv : 0 90 7 . 29 53 v 1 [ he p - ph ] 1 6 Ju l 2 00 9 DVCS and Vector Meson Production with H 1
Studies of the DVCS process and of exclusive VM production at HERA provide, in the presence of a hard scale, unique information on the mechanism of diffraction, in particular on the transition from soft to hard diffraction and spin dynamics. Exclusive final states studied by the H1 collaboration include real photons [2, 3] and light (ρ and φ [4, 5, 6]) and heavy VMs (J/ψ [7, 8], ψ(2s) [9] and Υ...
متن کاملDeeply Virtual Compton Scattering and Prompt Photon Production at Hera
Recent results on the Deeply Virtual Compton Scattering (DVCS) and prompt photon productions from H1 and ZEUS experiments on the ep collider HERA are presented. A new DVCS cross section measurements of the H1 Collaboration, for photon virtualities Q > 4 GeV and photon-proton c.m.s. energy 30 < W < 140 GeV, are discussed and compared to NLO QCD calculations encoding Generalized Parton Distributi...
متن کاملPhoton diffractive scattering off proton at high t with the H1 detector
The diffractive photon scattering at high t is studied using the H1 detector at HERA in the photoproduction regime (Q ∼ 0). The process γp −→ γY has the final photon of large transverse momentum implying the presence of the hard scale t, allowing predictions of the perturbative QCD to be applied. The measurement is based on 36.9 pb−1 of data collected in the 1999–2000 running period. The cross–...
متن کاملPrompt Photons and Particle Momentum Distributions At
Recent results, obtained by the H1 and ZEUS collaborations, are presented on differential cross sections , for inclusive prompt photon production in DIS and for photoproduction of prompt photons accompanied by a hadronic jet. Also presented are cross sections of normalised scaled momentum distribution of charged final state hadrons, measured by H1 in DIS ep collisions at high Q 2 in the Breit f...
متن کاملElastic vector meson production and DVCS at HERA
Recent results from the H1 and ZEUS experiments are reviewed. The cross sections of elastic photoand electroproduction of the vector mesons φ and J/ψ are measured as functions of Q2,W and t. The large statistics and the large coverage in t and W allow the determination of the effective Regge exchange trajectories, which are found to be different from the soft pomeron trajectory. Shrinkage is ob...
متن کامل