相关论文: Photon Contribution to the ``Super-hard" Pomeron
We investigate in detail the effect of a direct pomeron coupling to quarks on the production of jets in $ep$ scattering with almost real photons. Jet production via a direct pomeron coupling is compared with the resolved--pomeron mechanism.…
Inclusive jet cross sections for events with a large rapidity gap with respect to the proton direction from the reaction $ep \rightarrow jet \; + \; X$ with quasi-real photons have been measured with the ZEUS detector. The cross sections…
Two types of penetrating probes, direct photon and QCD jets, are investigated in the background of a small and rapidly expanding droplet of quark-gluon plasma. The additional thermal electromagnetic radiation results in a $\sim$50\%…
In this contribution we study for the first time the prompt photon production in single and double diffractive processes considering the resolved Pomeron model. We estimate the rapidity and transverse momentum dependence of the cross…
Direct photons are a powerful probe to study the properties of the unique matter created in ultrarelativistic heavy-ion collisions. They carry information on the various stages of a heavy-ion collision. At different transverse momenta (pT),…
Within the resolved Pomeron model of hard diffractive scattering, we compute prompt photon production in double-Pomeron-exchange events in proton-proton collisions. Using specific kinematical constraints chosen according to the acceptances…
We investigate the effect of a direct pomeron coupling to quarks on inclusive jet production in DIS and photoproduction. The direct pomeron coupling generates a point-like contribution to the diffractive part of the structure function…
The production of prompt photons in photoproduction reactions in the ZEUS experiment is discussed. Cross sections for inclusive prompt photons and for prompt photons accompanied by jets are compared with theory, and the latter are used to…
Direct photons are a powerful tool for elucidating the properties of the hot QCD matter in heavy-ion collisions. They are conventionally estimated by assuming prompt photon contributions in proton-proton collisions and thermal and prompt…
The photoproduction of isolated photons has been measured in diffractive events recorded by the ZEUS detector at HERA. Cross sections are evaluated in the photon-proton transverse-energy and pseudorapidity ranges 5<ET(gamma)<15 GeV and…
We consider hard diffractive events in proton-proton collisions at the LHC, in which both protons escape the collision intact. In such double Pomeron exchange processes, we propose to measure dijets and photon-jet final states, and we show…
We discuss the transverse momentum distribution of thermal and prompt photons in ultrarelativistic heavy ion collisions. The prompt photons are mostly produced by fragmentation of quark jets (bremsstrahlung). If these quark jets suffer a…
Jet tomography, the study of differential energy loss of hard scattered partons to infer the density profile of the medium, is greatly improved by precise knowledge of the initial energy of the hard probe. As photons are not strongly…
We investigate the effect of a direct pomeron coupling to quarks in DIS and photoproduction of jets. The direct pomeron coupling generates a point-like contribution to the diffractive part of the structure function $F_2$, which is analysed…
We present direct photon-hadron correlations in 200 GeV/A Au$+$Au, $d$$+$Au and $p$$+$$p$ collisions, for direct photon $p_T$ from 5--12 GeV/$c$, collected by the PHENIX Collaboration in the years from 2006 to 2011. We observe no…
The production of hadronic final states in electron-positron or electron-hadron collisions is induced predominantly by quasi-real photons that were emitted off incoming leptons. In these processes, the photon either enters directly or…
The present theoretical knowledge about photons and hard photoproduction processes, i.e. the production of jets, light and heavy hadrons, quarkonia, and prompt photons in photon-photon and photon-hadron collisions, is reviewed. Virtual and…
Results from the PHENIX experiment on direct-photon production in Au+Au collisions at sqrt{s_{NN}} = 200 GeV for transverse momenta 1 < p_T < 13 GeV/c are presented. Direct-photon yields at high p_T scale as expected for particle production…
We analyze contributions to the heavy vector meson production with large transverse momentum in proton--proton and diffractive photon--proton scattering driven by an exchange of two Balitsky--Fadin--Kuraev--Lipatov Pomerons in the squared…
In this paper we present a detailed comparison of the dijet production by photon -- photon, photon -- pomeron and pomeron -- pomeron interactions in $pp$, $pA$ and ${\rm AA}$ collisions at the LHC energy. The transverse momentum, pseudo --…