Related papers: Quarks vs. gluons in exclusive rho electroproducti…
We present an analysis of genuine twist-3 quark contributions to the amplitude of exclusive electro-production of transversely polarized vector mesons. Using the formalism based on the momentum representation we calculated all the genuine…
We summarize the formalism for calculating the exclusive dijet production in $e p \to e^{\prime} jj p$ in collinear QCD factorization, using generalized parton distributions as the soft hadronic input modeled in the double distribution…
We perform an analysis of the relation between the factorization scale and the masses of the quarks in the calculation of the hard gluon coefficient in polarized deep inelastic scattering. Particular attention is paid to the role of strange…
We study the associated production of an electroweak vector boson and the Higgs boson with a jet via gluon-gluon fusion. At the leading order, these processes occur at one-loop level. The amplitudes of these one-loop processes are gauge…
I discuss exclusive production of the $\eta'$, $J/\psi$, and $\chi_c(0^+)$ mesons in $pp$ and $p \bar p$ collisions at high energies. QCD diffractive mechanisms as well as nondiffractive mechanisms are discussed. Different unintegrated…
The effects of gluon radiation by charm quarks on the transport coefficients {\it e.g.} drag, longitudinal and transverse diffusion and shear viscosity have been studied within the ambit of perturbative quantum chromodynamics (pQCD) and…
We present results for higher-order soft-gluon radiative corrections for single top-quark production in association with electroweak bosons, including $t\gamma$ and $tZ$ production via anomalous FCNC couplings. We provide results for the…
We discuss diffractive dissociation of gluons into heavy quark pairs. The particular mechanism is similar to the diffractive dissociation of virtual photons into quarks, which drives diffractive deep inelastic production of charm in the…
We present a study of heavy quarkonium production in hard diffractive process by the Pomeron exchange for Tevatron and LHC energies. The numerical results are computed using recent experimental determination of the diffractive parton…
Under very general assumptions we show that the quark dispersion relation in the quark-gluon plasma is given by two collective branches, of which one has a minimum at a non-vanishing momentum. This general feature of the quark dispersion…
We consider three jet production at high $p_T$ in the $\gamma\gamma \to q \bar q g$ process and calculate quark and gluon jet spectra. The possibility of quark-gluon jet separation is discussed and compared with the $e^+ e^- \to q \bar q g$…
A calculation of thermal gluon decay shows that this process contributes significantly to strangeness production in a quark-gluon plasma. Our analysis does not support recent claims that this is the dominant process. In our calculations we…
We investigate the exclusive proton-induced $K^+$ production near the kaon threshold. Compared are two models: a meson-exchange model, which includes $\pi$, \rho$, $K$ and $K^\ast$ exchange, together with the dominant baryon resonances, and…
The exchange of gluons between heavy quarks produced in $e^+e^-$ interactions results in an enhancement of their production near threshold. We study QCD threshold effects in $\gamma\gamma$ collisions. The results are relevant to heavy quark…
We consider the experimental ratios of multistrange to strange antibaryon production and compare them to the standard Quark-Gluon String Model predictions. The significant differences between the experimental bar(Xi)+/bar(Lambda) and,…
The effect of one-gluon-exchange (OGE) pair-currents on the ratio $\mu_p G_E^p/G_M^p$ for the proton is investigated within a nonrelativistic constituent quark model (CQM) starting from $SU(6) \times O(3)$ nucleon wave functions, but with…
Exclusive quarkonium photo- and electro-production off the nucleon is studied in the framework of generalized parton distributions (GPDs). The short distance part of the process is treated at leading order in perturbative Quantum…
Based on the two Higgs doublet model, we study the effect of Higgs-boson exchange on the (super)heavy quarkonium \bar QQ, which induces a strong attractive force between a (super)heavy quark Q and an antiquark \bar Q. An interesting…
We investigate whether and how different fragmentation properties of quarks and gluons affect identified particle spectra. We present a systematic study of $\pi$, $K$ and $p$ production in minimum bias (inelastic, non-diffractive), two- and…
Exclusive incoherent electroproduction of the rho^0(770) meson from 1H, 2H, 3He, and 14N targets has been studied by the HERMES experiment at squared four-momentum transfer Q**2>0.4 GeV**2 and positron energy loss nu from 9 to 20 GeV. The…