Related papers: Perturbative QCD of hard and soft processes
Transport theory is an efficient approach to derive an effective theory for the soft modes of QCD at high temperature. It is known that the leading order operators of this theory can be obtained from (semi-classical) kinetic equations of…
The analytical perturbative approach, if taken to the limit of its applicability, allows one to predict an energy independent limit for the one-particle invariant density in QCD jets E dn/d^3p at very small momenta p. This is a direct…
We derive the quantum dynamics of heavy quark systems in quark-gluon plasma as open quantum systems. The scatterings of a heavy quark with the hard medium particles give rise to Debye screened QCD force and drag force and its fluctuation.…
We review recent calculations of second order corrections to heavy quark decays. Techniques developed in this context are applicable to many processes involving heavy charged particles, for example the nonabelian dipole radiation.…
The present calculations in perturbative QCD reach the order $\alpha_s^4$ for several correlators calculated to five loops, and the huge computational difficulties make unlikely the full six-loop calculation in the near future. This…
The gradient flow in QCD is treated perturbatively through next-to-next-to-leading order in the strong coupling constant. The evaluation of the relevant momentum and flow-time integrals is described, including various means of validation.…
Effective field theory methods provide a convenient approach to study static observables in field theory at finite temperature. In this talk, I will outline the construction of the effective field theory that describes effective observables…
The subject of the first section-lecture is concerned with the strength and the weakness of the perturbation theory (PT) approach, that is expansion in powers of a small parameter $\alpha$, in Quantum Theory. We start with outlining a…
We compare two approaches to the description of pion Compton scattering at moderate momentum transfer, one being based on local duality QCD sum rules for the invariant amplitudes of the process, which have been derived recently, and the…
QED radiative corrections to elastic electron-proton scattering at low energies are discussed. Corrections to the electron line and effects due to vacuum polarization are computed. Higher order effects are estimated for the conditions of…
We study the graviton Regge trajectory in Holographic QCD as a model for high energy scattering processes dominated by soft pomeron exchange. This is done by considering spin J fields from the closed string sector that are dual to glueball…
We discuss two types of contributions to hadronic form factors in QCD: hard gluon exchange and soft wave function overlap. Within the QCD sum rule approach, the hard contribution has strong numeric suppression by factor (\alpha_s/\pi) ~ 0.1…
In this thesis I study the infrared limits of QCD beyond leading power by developing effective quantum field theory techniques. I introduce the motivations for studying this subject both as a tool to deepen our understanding of the infrared…
QCD-based analysis of nonfactorizable parts of weak nonleptonic amplitudes is reported. Nonperturbative effects due to soft gluon exchange play a key role leading to the emergence of a dynamical rule of discarding $1/N_c$ corrections.
We determine the analytic expression of the damping rates for very soft moving quarks in an expansion to second order in powers of their momentum in the context of QCD at high temperature. The calculation is performed using the…
We discuss the question of the relevance of perturbative QCD calculations for analyzing the properties of the dense medium produced in heavy ion collisions. Up to now leading order perturbative estimates have been worked out and confronted…
The search for new phenomena at hadron colliders requires a good understanding of QCD processes. The analysis of multi-jet signatures in the top quark search at the Tevatron is one example, forward jet-tagging and rapidity gap techniques in…
Non-relativistic bound state theories for QED and QCD have become fairly mature and amenable to a textbook-level understanding and computation. In this talk we give an introductory review of the following subjects related to the recent…
The $^{1}$H($e,e^\prime \pi^+$)n cross section was measured for a range of four-momentum transfer up to $Q^2$=3.91 GeV$^2$ at values of the invariant mass, $W$, above the resonance region. The $Q^2$-dependence of the longitudinal component…
An unknown small-x behavior of nucleon structure functions gives appreciable uncertainties to high-energy neutrino-nucleon cross-sections. We construct structure functions using at small x Regge inspired description by A. Donnachie and P.…