Related papers: Soft-Gluon Cancellation, Phases and Factorization …
We derive a factorization theorem that allows for resummation of small-$x$ logarithms by exploiting Glauber operators in the soft collinear effective field theory. Our analysis is carried out for the hadronic tensor $W^{\mu\nu}$ in deep…
The study of amplitudes and cross sections in the soft and collinear limits allows for an understanding of their all orders behavior, and the identification of universal structures. At leading power soft emissions are eikonal, and described…
We present factorization theorems for two exclusive heavy-quarkonium production processes: production of two quarkonia in e^+e^- annihilation and production of a quarkonium and a light meson in B-meson decays. We describe the general proofs…
Since an old observation by Beenakker et al, the evaluation of QCD processes in dimensional reduction has repeatedly led to terms that seem to violate the QCD factorization theorem. We reconsider the example of the process gg->ttbar and…
The role of soft (non-perturbative) gluons in collinear parton densities and parton shower event generators is investigated with the Parton Branching method as a solution of the DGLAP evolution equations. It is found that soft gluons play a…
General expressions for the impact factors up to terms vanishing at the space-time dimension $D\rightarrow 4$ are presented. Their infrared behaviour is analysed and calculation of exact in $D\rightarrow 4$ asymptotics at small momenta of…
The Lorentz contraction of ultrarelativistic nuclei entails a spatial overlap and fusion (recombination, saturation) of partons belonging to different nucleons at the same impact parameter. In these lectures we present a consistent…
Shortened table of contents: 1. Introduction 1.1 The Standard Model of Elementary Particles 1.2 The Quantum Nature of Gauge Fields 2. Soft Gluon Resummation 2.1 Lepton Pair Production at Fixed Order in $\alpha _s$ 2.2 The Resummation…
We explore the connection between the factorisation of virtual corrections to multi-particle massless gauge theory amplitudes and the problem of subtraction at NNLO and beyond. Taking inspiration from virtual factorisation, we provide a set…
We study long-distance singularities governing different physical quantities involving massless partons in perturbative QCD by using factorisation in terms of Wilson-line correlators. By isolating the process-independent hard-collinear…
We describe the taming effect induced by soft gluon $k_t$-resummation on the rapid rise of QCD mini-jet contributions to the total cross-sections.This results from an eikonal model in which the rise of the total cross-section is due to…
We present two things in this discussion. First, we develop and prove the theory of the extension of the YFS Monte Carlo approach to higher order SU_{2L} x U_1 radiative corrections to the analogous higher order QCD radiative corrections.…
We study the single parton fragmentation functions (FFs) at the input factorization scale $\mu_0\gtrsim 2m_Q$, with heavy quark mass $m_Q$, in the soft gluon factorization (SGF) approach. We express the FFs in terms of perturbatively…
I discuss some of the basic techniques and results of soft gluon resummation, and their applications to scattering at collider energies.
An essential part of high-energy hadronic collisions is the soft hadronic activity that underlies the primary hard interaction. It includes soft radiation from the primary hard partons, secondary multiple parton interactions (MPI), and…
An energetic parton travelling through a quark-gluon plasma loses energy via occasional hard scatterings and frequent softer interactions. Whether or not these interactions admit a perturbative description, the effect of the soft…
We study the gluon parton densities [parton distribution functions (PDFs), transverse momentum distributions (TMDs), generalized parton distributions (GPDs)] and form factors in soft-wall AdS/QCD. We show that the power behavior of gluon…
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…
We present some results on renormalization and factorization scale dependence of soft-gluon resummation, at the next-to-leading-logarithmic level, in the fixed-target hadro-production cross-section for prompt photons.
The resummation of threshold logarithms for direct photon production cross sections in hadronic collisions is presented. The resummation is based on the factorization properties of the cross section and is formulated at next-to-leading…