相关论文: Two-Photon Processes at Intermediate Energies
The bosonized QCD2+QED2 system for quarks with two flavors contains QCD2 and QED2 bound states, with an isoscalar photon at about 25 MeV and an isovector (I=1,I_3=0) photon at about 44 MeV. Consequently, when a quark and an antiquark at the…
The inclusive production of charged hadrons in the collisions of quasi-real photons e+e- -> e+e- +X has been measured using the OPAL detector at LEP. The data were taken at e+e- centre-of-mass energies from 183 to 209 GeV. The differential…
The hadroproduction of lepton pairs with mass $Q$ and transverse momentum $Q_T$ can be described in perturbative QCD by the same partonic subprocesses as prompt photon production. We demonstrate that, like prompt photon production, lepton…
The reactions gamma p -> K+ Lambda and gamma p -> K* Lambda are analyzed within perturbative QCD, allowing for diquarks as quasi-elementary constituents of baryons. The diquark-model parameters and the quark-diquark distribution amplitudes…
The next generation of $e^+e^-$-colliders will offer a possibility of clean testing of QCD dynamics in the Regge limit. Recent progress in the theoretical description of exclusive processes permits for many of them a consistent use of the…
The presence of two photon exchange in $ep$ elastic scattering and in the crossed processes ($\bar p +p\leftrightarrow \ell^+ +\ell^-$, $\ell=e$ or $\mu$) is discussed in terms of three complex amplitudes which are functions of two…
The photoprodution of doubly heavy baryon ($\Xi_{cc},\Xi_{bb},\Xi_{bc}$) is investigated in the context of future high-energy and high-luminosity $e^+e^-$ colliders. The study incorporates two sources of initial photons, namely the LBS…
Two photon collisions offer a variety of physics studies that can be performed at the future electron-positron colliders. Using the planned CEPC parameters as a benchmark we consider several topics to be studied in the two-photon…
Photoproduction of a pair of particles with large invariant mass is a natural extension of collinear QCD factorization theorems which have been much studied for deeply virtual Compton scattering and deeply virtual meson production. We…
In this short review paper, we discuss some of the recent advances in the field of parton fragmentation processes into hadrons as well as their possible modifications in QCD media. Hadron production data in e+e-, deep inelastic scattering…
We study the exclusive electroproduction of a photon pair in the kinematical regime where the diphoton invariant mass is large and where the nucleon flies almost in its original direction. We discuss the relative importance of the QCD…
We investigate the properties of the QCD matter across the deconfinement phase transition in the scope of the parton-hadron string dynamics (PHSD) transport approach. We present here in particular the results on the electromagnetic…
The QCD phenomenology of prompt photon production from e-p to p-p/p-pbar and A-A collisions is reviewed. The use of prompt photons as a probe of (i) parton distribution functions (in a proton or in nuclei) as well as (ii) fragmentation…
Differences in the photoproduction of mesons on the free proton and on nuclei are expected to reveal changes in the properties of hadrons. Double pion photoproduction from nuclei has been used to investigate the in medium modification of…
We perform a QCD analysis of the exclusive production of two mesons in gamma^* gamma collisions in the kinematical domain of large photon virtuality Q and small hadronic invariant mass W. This reaction is dominated by a scale invariant…
The cross sections for the production of hadrons in quasi-real photon-photon collisions in proton-proton and heavy ion interactions are compared with the corresponding cross sections for central diffraction and for photon-pomeron…
We consider the charge-odd correlations (COC) in cross sections of processes of production of charged particles. The cases of a muonic pair and pion systems $\pi^{+}\pi^{-},\pi^{+}\pi^{-}\pi^{0}$ are considered in detail for electron-proton…
Generalized parton distributions (GPDs) enter QCD factorization theorems for hard exclusive reactions. They encode rich information about hadron partonic structure. We explore a possibility to constrain GPDs in experiments at LHC…
We study the exclusive double-photon annihilation processes, $e^+ e^- \to \gamma \gamma^\ast\to \gamma V^0$ and $e^+ e^- \to \gamma^\ast \gamma^\ast \to V^0_a V^0_b,$ where the $V^0_i$ is a neutral vector meson produced in the forward…
We consider the exclusive photo-production of a photon-meson pair with a large invariant mass, working in the QCD factorisation framework. Explicitly, we consider a $ \rho $-meson or a charged $ \pi $ in the final state. This process gives…