Related papers: The Exclusive NLO DGLAP Kernels for Non-Singlet Ev…
In this paper I show that it is possible to use Regge theory to constrain the initial parton distribution functions of a global DGLAP fit. In this approach, both quarks and gluons have the same high-energy behaviour which may also be used…
We study contributions from nonperturbative effects and parton showering in NLO event generators, and present applications to jet final states. We find pT-dependent and rapidity-dependent corrections which can affect the shape of observed…
In this work, a new Monte-Carlo simulation of double parton scattering (DPS) at parton level is presented. The simulation is based on the QCD framework developed recently by M. Diehl, J. R. Gaunt and K. Sch\"{o}nwald. With this framework,…
To explore the interplay of NLO matching and next-to-leading logarithmic (NLL) parton showers, we consider the simplest case of $\gamma^*$ and Higgs-boson decays to $q\bar q$ and $gg$ respectively. Not only should shower NLL accuracy be…
We present the elements of the IR-improved DGLAP-CS theory as it relates to the new MC friendly exponentiated scheme for precision calculation of higher order corrections to LHC physics in which IR singularities from both QED and QCD are…
Parton shower event generators typically approximate evolution of QCD color so that only contributions that are leading in the limit of an infinite number of colors are retained. Our parton shower generator, Deductor, has used an "LC+"…
We present the recent developments in exact amplitude-based resummation methods for non-Abelian gauge theories as they relate to precision LHC physics. We discuss QEDXQCD exponentiation, shower/ME matching, IR-improved DGLAP-CS theory and…
We study factorization schemes for parton shower models in hadron-hadron collisions. As an example, we calculate lepton pair production mediated by a virtual photon in quark--anti-quark annihilation, and we compare factorized cross sections…
We consider the singular behaviour of one-loop QCD matrix elements when several external partons become simultaneously parallel. We present a new factorization formula that describes the singular collinear behaviour directly in colour…
We present the polarized parton distribution functions from a QCD analysis of the worldwide polarized deep inelastic scattering data, based on the dynamical parton distribution model. All the sea quarks and gluons are dynamically generated…
DGLAP evolution equations may be presented in a form completely analogous to the Boltzmann equation. This provides a natural proof of the positivity of the spin-dependent parton distributions, provided the initial distributions at $Q^2_0$…
In this paper we make predictions for nondiagonal parton distributions in a proton in the LLA. We calculate the DGLAP-type evolution kernels in the LLA, solve the nondiagonal GLAP evolution equations with a modified version of the…
Recent developments in QCD phenomenology have spurred on several improved approaches to Monte Carlo event generation, relative to the post--LEP state of the art. In this brief review, the emphasis is placed on approaches for 1) consistently…
We propose a novel hybrid model for jet quenching, including both strong and weak coupling physics where each seems appropriate. Branching in the parton shower is assumed to be perturbative and described by DGLAP evolution, while…
We present a method to match the multi-parton states generated by the High Energy Jets Monte Carlo with parton showers generated by the Ariadne program using the colour dipole model. The High Energy Jets program already includes a full…
In this work, we present an analytical solution for QCD$\otimes$QED coupled Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations at the leading order (LO) accuracy in QED and next-to-leading order (NLO) accuracy in…
The possibility of an improvement of current NLO Monte Carlo event generators by means of choosing a suitable factorization scheme is studied. The optimal factorization scheme for combining initial state parton showers and NLO hard…
We develop a framework for the reconstruction of the non-forward kernels which govern the evolution of twist-two distribution amplitudes and off-forward parton distributions beyond leading order. It is based on the knowledge of the special…
We report on a major milestone in the construction of logarithmically accurate final-state parton showers, achieving next-to-next-to-leading-logarithmic (NNLL) accuracy for the wide class of observables known as event shapes. The key to…
We outline a new formalism for dipole-type parton showers which maintain exact energy-momentum conservation at each step of the evolution. Particular emphasis is put on the coherence properties, the level at which recoil effects do enter…