相关论文: Isolated photons in perturbative QCD
Exclusive $C=+1$ scalar, axial-vector, and tensor quarkonium production in high-energy electron-proton scattering requires a $C$-odd $t$-channel exchange of a photon or a three gluon ladder. We derive the expressions for the corresponding…
One of the challenges of collider physics is to unambiguously associate detector based objects with the corresponding elementary physics objects. A particular example is the association of calorimeter-based objects such as "jets",…
This Ph.D.~thesis is divided into two distinct parts. The first part focuses on hard exclusive scattering processes in Quantum Chromodynamics (QCD) at high energies, while the second part delves into spin phenomena at the Large Hadron…
Photon-photon collisions are investigated in the framework of the two-component Dual Parton Model. The model is shown to agree well to hadron production data from hadron-hadron and photon-hadron collisions. The multiparticle production in…
An event generator for diphoton ($\gamma\gamma$) production in hadron collisions that includes associated jet production up to two jets has been developed using a subtraction method based on the LLL subtraction. The parton shower (PS)…
Several sources of direct photons are known to contribute to the total photon yield in high energy nuclear collisions. All of these photons carry characteristic and important information on the initial nuclei or the hot and dense fireball…
We discuss the recent developments in the study of single photon production in relativistic heavy ion collisions. In particular their production at SPS, RHIC, and LHC energies is re-examined in view of the results of Aurenche et al which…
The next generation of $e^+e^-$ colliders will offer a possibility of clean testing of QCD dynamics. Recent progress in the theoretical description of exclusive processes permits for many of them a consistent use of the perturbative QCD…
Direct photon production is an important observable in heavy ion collisions as photons are penetrating and therefore largely insensetive to final state effects that lead to jet quenching. Measurements of the fragmentation component to…
We re\,examine the theory of hadronic photon-nucleon interactions at the quark-gluon level. The possibility of multiple parton collisions in a single photon-nucleon collision requires an eikonal treatment of the high-energy scattering…
We consider the production of prompt-photon pairs at the LHC and we report on a study of QCD radiative corrections up to the next-to-next-to-leading order (NNLO). We present a detailed comparison of next-to-leading order (NLO) results…
High intensity back-scattered laser beams will allow the efficient conversion of a substantial fraction of the incident lepton energy into high energy photons, thus significantly extending the physics capabilities of an electron-electron or…
A complete next-to-leading order QCD calculation of deep inelastic electron-photon scattering including direct and resolved real photon components is presented. Soft and collinear singularities are extracted using the phase space slicing…
Recent results from ZEUS for inclusive jet cross sections, dijet cross sections and dijet angular distributions are compared with NLO perturbative QCD calculations. The observation of isolated high $P_T$ photons (prompt photons) is also…
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…
It is generally assumed that due to factorization of long- and short-distance dynamics perturbative QCD can be applied to exclusive hadronic reactions at large momentum transfers. Within such a perturbative approach diquarks turn out to be…
We calculate the production of real photons in relativistic nuclear collisions at RHIC, consistently with the quenching of fast partons. We go beyond one-body observables, and evaluate photon-triggered fragmentation functions, in the…
Building on earlier work, the dipole subtraction formalism for photonic corrections is extended to various photon--fermion splittings where the resulting collinear singularities lead to corrections that are enhanced by logarithms of small…
Direct (prompt) photon production is a field of very high interest in hadron colliders. It provides probes to search for new phenomena and to test QCD predictions. In this article, two recent cross-section results for direct photon…
We study the impact of differential isolated-photon+jet cross sections measured in proton-proton collisions at a center-of-mass energy of sqrt{s} = 7 TeV on the parton distribution functions (PDF) of the proton. Next-to-leading order…