Related papers: Perturbative Universality in Soft Particle Product…
Jet physics in relativistic heavy ion collisions, which combines perturbative QCD jet production with quark and gluon energy loss and in-medium parton shower modification, has emerged as a powerful tool to probe the properties of…
Working to all orders in dimensionally-regularized QCD, we study the radiation of a photon whose energy is much lower than that of external partons, but much larger than the masses of some quarks. We argue that the conventional soft photon…
We use QCD to compute the cross section for coherent production of a di-jet (treated as a $q\bar q$ moving at high relative transverse momentum,$\kappa_t $). In the target rest frame,the space-time evolution of this reaction is dominated by…
The study of gluon radiation in QCD, in the limit of small ("soft") momentum, remains an active research area, with a variety of phenomenological and theoretical applications. Soft gluon emission leads to large logarithms in perturbation…
An improved generalized suppression factor for gluon emission off a heavy quark is derived within perturbative QCD, which is valid for the full range of rapidity of the radiated gluon and also has no restriction on the scaled mass of the…
The basic ideas and some results of the semiclassical approach to diffractive DIS are briefly described. In the production of high-$p_{\perp}$ jets boson-gluon fusion is predicted to be the dominant partonic process. The…
Anomalous soft photons in excess of what is expected from electromagnetic bremsstrahlung have been observed in association with the production of hadrons, mostly mesons, in high-energy (K+)p, (pi+)p, (pi-)p, pp, and (e+)(e-) collisions. We…
We consider the radiation of three soft gluons in a generic process for multiparton hard scattering in QCD. In the soft limit the corresponding scattering amplitude has a singular behaviour that is factorized and controlled by a colorful…
A selected set of topics along the borderline between perturbative and nonperturbative QCD in exclusive reactions are studied. Specific problems, related to different mechanisms of momentum transfer to an intact hadron, are discussed.…
In the framework of perturbative QCD in the fourth order over the $\alpha_s$ coupling constant for the production of two pairs of quarks and in the model of weak binding of the quarks into meson, the analysis of the hadronic production of…
In the events of the type $e^+e^- \rightarrow W^+W^- \rightarrow$ 4 jets, $e^+e^- \rightarrow t\bar{t} \rightarrow bW^+\bar{b}W^-$, particle production could depend in a non-trivial way on the kinematics of the process. It is shown that QCD…
We show that both hard perturbative and soft non-perturbative QCD effects are important in hadroproduction of charmonium. Observed $x_F$ and $p_\perp$ distributions of J/psi in fixed target experiments can be well described by our Monte…
A global QCD analysis of the direct photon production process from both fixed target and collider experiments is presented. These data sets now completely cover the parton $x$ range from 0.01 to 0.6, thereby providing a stringent test of…
The observation of jets in a variety of hard-scattering processes has allowed the quantitative study of perturbative quantum chromodynamics (PQCD) by comparing detailed theoretical predictions with a wide range of experimental data. This…
We discuss non-perturbative QCD contributions to jet observables, computing their dependence on the jet radius R, and on the colour and transverse momentum of the parton initiating the jet. We show, using analytic QCD models of power…
We report the results of calculations of inclusive soft hadron production in proton-lead collisions at the LHC in the framework of modified quark-gluon string model (QGSM) extended to $pA$ interactions. Our consideration involves the…
At very high energies, in the infinite momentum frame and in light cone gauge, a hard scale proportional to the high parton density arises in QCD. In an effective theory of QCD at small $x$, this scale is of order $\alpha_S\mu$, where $\mu$…
The production of low mass dileptons and soft photons from thermalized Quark Gluon Plasma (QGP) and hadronic matter in relativistic heavy ion collisions is evaluated. A boost invariant longitudinal and cylindrically symmetric transverse…
The duality between partonic and hadronic descriptions of physical phenomena is one of the most remarkable features of strong interaction physics. A classic example of this is in electron-nucleon scattering, in which low-energy cross…
Fragmentation Functions (FF) are universal non-perturbative objects that model hadronization in some general kind of processes. They are mainly extracted from experimental data, hence constraining the parameters of the corresponding fits is…