相关论文: Scattering Through QCD Sphalerons
Recently, a semiclassical approach to diffraction has been proposed, which treats the proton as a classical colour field. The present paper demonstrates that this approach is consistent with the concept of diffractive parton distributions.…
Contribution of simplest loops for hadron-nucleus scattering cross-sections is studied in the Local Reggeon Field Theory with a supercritical pomeron. It is shown that inside the nucleus the supercritical pomeron transforms into a…
We study QCD radiation in decay processes involving heavy particles. As input, the first-order gluon emission rate is calculated in a number of reactions, and comparisons of the energy flow patterns show a non-negligible process dependence.…
I discuss the theoretical status of the `soft' pomeron and its place in describing generic diffractive processes. The role of perturbative QCD (pQCD) corrections is considered, in particular in the context of quasi-elastic vector meson…
We consider spin asymmetries for prompt photon production in collisions of longitudinally polarized hadrons. This reaction will be a key tool at the BNL-RHIC pp collider for determining the gluon spin density in a polarized proton. We study…
We present a formalism for high energy soft processes, mediated by Pomerons, which embodies pion-loop insertions in the Pomeron trajectory, rescattering effects via a two-channel eikonal and high-mass diffractive dissociation. It describes…
Coalescence of minijet partons with the partons from the quark-gluon plasma formed in relativistic heavy ion collisions is suggested as the mechanism for production of hadrons with intermediate transverse momentum. The resulting enhanced…
A QCD formula for the polarization in the large-p_T \Lambda hyperon production in the unpolarized nucleon-nucleon collision at large x_F is derived. We focus on the mechanism in which the chiral-odd spin-independent twist-3 quark…
Scattering of two mesons is considered in the framework of two-dimensional QCD in the large-$N_c^{}$ limit with four different quark flavors. The scattering takes place through two coupled channels, corresponding to direct and…
Inclusive jet cross sections for events with a large rapidity gap with respect to the proton direction from the reaction $ep \rightarrow jet \; + \; X$ with quasi-real photons have been measured with the ZEUS detector. The cross sections…
Coherence, multiple scattering and the interplay between soft and hard processes are discussed. These physics phenomena are essential for understanding the nuclear dependences of rapidity density and $p_T$ spectra in high-energy heavy-ion…
Central pseudoscalar production in $pp$ scattering is suppressed at small values of $Q_\perp$, where $Q$ is defined as the difference between the momenta transferred from the two protons. Such a behaviour is expected if the production…
We discuss average properties of the gluon cascade generated by an energetic parton propagating through a dense QCD medium. The cascade is mostly made with relatively soft gluons, whose production is not suppressed by the LPM effect. Unlike…
Following recent works on production and subsequent explosive decay of QCD sphaleron-like clusters, we discuss the mechanism of quark pair production in this process. We first show how the gauge field explosive solution of Luscher and…
We analyze the contribution of pQCD based semi-hard parton (re)scattering to the reaction dynamics of relativistic heavy-ion collisions at SPS and RHIC. While such processes are able to account for the measured yield of high momentum direct…
By finding rare (but not exponentially rare) large-angle deflections of partons within a jet produced in a heavy ion collision, or of such a jet itself, experimentalists can find the weakly coupled short-distance quark and gluon particles…
In particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum…
Mechanism for the single transverse spin asymmeties in the pion production, p^\uparrow + p'\to \pi(\ell_T) + X, and the \Lambda hyperon polarization, p + p' \to \Lambda^\uparrow (\ell_T)+ X, is investigated in the framework of QCD…
We introduce generalized quark and gluon distributions in the deuteron, which can be measured in exclusive processes like deeply virtual Compton scattering and meson electroproduction. We discuss the basic properties of these distributions,…
Exclusive two-photon reactions such as Compton scattering at large angles, deeply virtual Compton scattering, and hadron production in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures…