Related papers: New results on small-x resummation for splitting f…
Starting from the one-loop divergences we obtained previously, we work out the renormalization of the Higgs-Electroweak Chiral Lagrangian explicitly and in detail. This includes the renormalization of the lowest-order Lagrangian, as well as…
Nonsinglet contributions to the $g_1(x,Q^2)$ structure function are calculated in the double-logarithmic approximation of perturbative QCD in the region $x \ll 1$. Double logarithmic contributions of the type $(\alpha_s \ln ^2 (1/x))^k$…
We present results from a recently completed project to calculate next-to-leading logarithmic resummed distributions for a variety of event shapes in the 1+1-jet limit of DIS. This allows fits for the strong coupling and for…
We present a formalism that resums threshold-enhanced logarithms to all orders in perturbative QCD for the rapidity distribution of any colorless particle produced in hadron colliders. We achieve this by exploiting the factorization…
An outstanding problem in QCD and jet physics is the factorization and resummation of logarithms that arise due to phase space constraints, so-called non-global logarithms (NGLs). In this paper, we show that NGLs can be factorized and…
It is well-known that direct analytic continuation of DGLAP evolution kernel (splitting functions) from space-like to time-like kinematics breaks down at three loops. We identify the origin of this breakdown as splitting functions are not…
The agreement between calculations inspired by the resummation of energy logarithms, known as BFKL approach, and experimental data in the semi-hard sector of QCD has become manifest after a wealthy series of phenomenological analyses.…
Perturbative cross-sections in QCD are beset by logarithms of kinematic invariants, whose arguments vanish when heavy particles are produced near threshold. Contributions of this type often need to be summed to all orders in the coupling,…
We extend the threshold resummation of the large logarithms $\ln x$ which appear in factorization formulas for exclusive $B$ meson decays, $x$ being a spectator momentum fraction, to the next-to-leading-logarithm (NLL) accuracy. It is shown…
We show how to use the Hopf algebra structure of quantum field theory to derive nonperturbative results for the short-distance singular sector of a renormalizable quantum field theory in a simple but generic example. We discuss renormalized…
The numerical effects of the known all-order leading and next-to-leading logarithmic small-$x$ contributions to the anomalous dimensions and coefficient functions of the unpolarized singlet evolution are discussed for the structure…
The study of hadronic jets and their substructure at hadronic colliders is crucial for improving our understanding of QCD, and searching for new physics. As such, there has been a significant effort to improve their theoretical description.…
We present precise resummed predictions for Higgs boson rapidity distribution through bottom quark annihilation at next-to-next-to-leading logarithmic (NNLL) accuracy matched to next-to-next-to-leading order (NNLO) and at…
We investigate the consistency requirements of the next-to leading BFKL equation with the renormalization group, with particular emphasis on running coupling effects and NL anomalous dimensions. We show that, despite some model dependence…
We review small $x$ contributions to perturbative evolution equations for parton distributions, and their resummation. We emphasize in particular the resummation technique recently developed in order to deal with the apparent instability of…
It is well understood that the leading logarithmic approximation for the amplitudes of high energy processes is insufficient and that the next-to-leading logarithmic effects are very large and lead to instability of the solution. The…
We study the region of small transverse momenta in qqbar- and gg-initiated processes with no colored particle detected in the final state. We present the universal expression of the O(alpha_s^2) logarithmically enhanced contributions up to…
We propose an improvement of the splitting functions at small x which overcomes the apparent problems encountered by the BFKL approach. We obtain a stable expansion for the x-evolution function chi(M) near M=0 by including in it a sequence…
We report the results of including resummed splitting functions in the QCD evolution equations at small x, and discuss the predictions that follow for the deep inelastic structure functions. *Contribution at XXX Rencontres de Moriond, Les…
An approximated solution for gluon distribution from DGLAP evolution equations with NLO splitting function in the small-$x$ limit is presented. We first obtain the simplified forms of LO and NLO splitting functions in the small-$x$ limit.…