相关论文: The photoproduction of vector mesons
We calculate polarization asymmetries in photoproduction of high transverse momentum mesons, focusing on charged pions, considering the direct, fragmentation, and resolved photon processes. The results at very high meson momentum measure…
We have studied in perturbative QCD all independent helicity amplitudes describing the photoproduction of light vector mesons at large $t$. We found a new hard production mechanism which is related to the possibility for a real photon to…
In this paper we analyze the photoproduction of heavy quarkonia pairs which include $b$-quarks, such as $B_{c}^{+}B_{c}^{-}$-mesons or charmonium-bottomonium pairs. Compared to charmonia pair production, these channels get contributions…
Inclusive studies of nuclear photoabsorption have provided clear evidence of medium modifications in the properties of hadrons. However, the results have not been explained in a model independent way. A deeper understanding of the situation…
The presently available data for the reaction ${\gamma}p{\to}\eta^\prime{p}$ are analyzed in terms of a model in which the dominant production mechanism is the exchange of the vector mesons $\omega$ and $\rho$. To describe the data at…
Vector meson photoproduction offers the opportunity to image target nuclei. The two-dimensional Fourier transform $d\sigma_{\rm coherent}/dt$ of coherent vector meson photoproduction gives the two-dimensional distribution of interaction…
In a transport model that combines initial state interactions of the photon with final state interactions of the produced particles we present a calculation of inclusive photoproduction of mesons in nuclei in the energy range from 1 to 7…
The strong electromagnetic fields of short duration associated with relativistic heavy ions make a heavy-ion collider a unique tool to study two-photon and photonuclear collisions. In this talk, we introduce the principles of…
We study the production asymmetry of charm versus anticharm mesons in photon-proton interactions. We consider photon gluon fusion plus higher order corrections in which light quarks through vector meson-proton interactions contribute to the…
It is shown that existence of a large anomalous chromomagnetic moment of quark induced by non-perturbative structure of QCD leads to the additional contribution to exclusive $\rho$-meson electroproduction off proton target. The significant…
We calculate the inclusive and diffractive photoproduction of heavy quarks in proton-proton collisions at Tevatron and LHC energies, where the photon reaches energies larger than those ones accessible at DESY-HERA. The integrated cross…
We review our recent results on exclusive production of $\mu^+ \mu^-$, heavy quark-antiquark, and meson-antimeson pairs in ultraperipheral, ultrarelativistic heavy ion collisions.
The study of photoproduction reactions has gained a unique opportunity with the HERA data. The high center of mass energy allows to carry out quantitative tests of QCD, to explore the substructure of both the photon and the proton and to…
In the framework of the constituent quark model the exclusive pair production of the charmed mesons in the photon-photon interaction is calculated. The comparison of these predictions with the ones of the heavy quark effective theory is…
We make predictions for the cross sections of coherent photoproduction of $\rho$, $\phi$, $J/\psi$, $\psi(2S)$, and $\Upsilon(1S)$ mesons in Pb-Pb ultraperipheral collisions (UPCs) at $\sqrt{s_{NN}}=5.02$ TeV in the kinematics of run 2 at…
Properties of hadrons and their modification within strongly interacting matter provide a link between experimental observables and Quantum Chromodynamics (QCD) in the non-perturbative sector. The sensitivity of various observables to…
We present predictions for the exclusive and dissociative production of vector mesons off protons in an electron-ion collider. The computation is based on the energy-dependent hot spot model that has successfully described the available…
Relying on the collinear factorization approach, we demonstrate that H1 and ZEUS measurements of exclusive light vector meson and photon electroproduction cross sections can be simultaneously described for photon virtualities of $Q >2 GeV$.…
The cross section for vector leptoquark production in electron--gluon collisions is calculated analytically using the Lagrangian with the minimal couplings between the leptoquarks and the gauge fields of the standard model. It is found that…
We discuss a collective effect, which can be possible in hadron--hadron collisions at superhigh energies, that is, a quasi-diffraction production of several white clusters of quarks and gluons. Being transformed into hadrons, such clusters…