Related papers: Direct vs. resolved photon: an exercise in factori…
We have calculated diffractive dijet production in deep-inelastic scattering (DIS) at low-Q^2 and next-to-leading order (NLO) of perturbative QCD, including contributions from direct and resolved photons. We study how the cross section…
The $\gamma\gamma\to\pi\pi$ reactions are discussed. To describe those processes, we include dipion continuum, resonances, high-energy pion-pion rescatterings, $\rho$ meson exchange and pQCD Brodsky-Lepage mechanisms. The cross section for…
Recent results from NLO QCD calculations for inclusive jet cross sections in gamma^*-gamma scattering at e+e- colliders, especially for LEP, are reported. The virtuality Q^2 of the virtual photon is non-zero and can be unlimited large. The…
By making use of an explicit representation for the imaginary part of the photon polarization tensor in terms of transitions between the Landau levels of light quarks, we study the angular dependence of direct photon emission from a…
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…
We present the first calculation of inclusive jet photoproduction with next-to-next-to-leading order (NNLO) contributions, obtained from a unified threshold resummation formalism. The leading coefficients for direct photoproduction are…
We calculate the nuclear dependence of direct photon production in hadron-nucleus collisions. In terms of a multiple scattering picture, we factorize the cross section for direct photon production into calculable short-distance partonic…
A high-energy lepton-lepton collider will give us a unique possibility to study e-gamma and gamma-gamma interactions at high energies. The high-energy photons can be generated by Compton back-scattering of laser light on the high-energy…
The theoretical framework for a next-to-leading order QCD analysis of the spin-dependent parton densities Delta f^{gamma}(x,Q^2) of the longitudinally polarized photon and of its structure function g_1^{gamma}(x,Q^2) is reviewed in some…
We review several most recent prompt-photon measurements at HERA and the Tevatron and discuss their implication for future measurements at the LHC. A comparison to Monte Carlo models, as well as to NLO QCD predictions based on the standard…
Measurements of jet production in the photoproduction region at HERA are presented, which are sensitive to the underlying event structure. It is argued that in the photoproduction region a significant amount of multi-parton interactions in…
Direct photon spectra and elliptic flow v2 in heavy-ion collisions at RHIC and LHC energies are investigated within a relativistic transport approach incorporating both hadronic and partonic phases - the Parton-Hadron-String Dynamics…
The cross section for photoproduction of an isolated prompt photon in association with a jet is studied in Next-to-Leading Order. The kinematics are those appropriate for the DESY $ep$ collider HERA. The effects on the cross section of…
Quantum electrodynamics in a laser is formulated, in which the electron-laser interaction is exactly considered, while the interaction of an electron and a single photon is considered by perturbation. The formulation is applied to the…
The Polaron is the quantum of a "Polarization" field originated by the "contact" interaction [D1][D2] of a massive polarizable particle with a photon. We prove that this process produces bound states. Each bound state carries a…
We discuss the role of collisional energy loss on high $p_T$ photon data measured by PHENIX collaboration by calculating photon yield in jet-plasma interaction. The phase space distribution of the participating jet is dynamically evolved by…
The discussion of the large elliptic flow of direct photons in Quark Matter 2014 has been reviewed. Then based on previous technique work, the physics meaning related to the large elliptic flow of direct photons is invetigated in this…
Previous work on soft-gluon resummation for direct photon production is extended to include additional subleading logarithmic terms through O(alpha alpha_s^3) and some representative comparisons are made to experimental results from the…
Results of a next-to-leading order calculation of the inclusive cross section for a photon and a heavy quark (charm or bottom), $p \bar p / pp \to \gamma +Q +X$, are presented. Pointlike photon subprocesses through ${\cal…
A theoretical possibility to determine the proton Compton scattering cross section from the reaction $ep\rightarrow ep\gamma$ is studied in the kinematics with a small transversal momentum transfer in the electron leg. With the exception of…