1,721,058 research outputs found
QT and Φ* observables in Drell-Yan processes
No full textWe describe results on the phenomenology of electro-weak bosons produced in hadron-hadron collisions. In particular, we discuss the Φ* variable, which enables us to probe the low-transverse-momentum region of lepton pairs produced via the Drell-Yan mechanism with unprecedented experimental accuracy. We describe state-of-the-art theoretical calculations for Φ* and their comparison to Tevatron and LHC data
Combining Q(T) and small-x resummations
No full textWe analyze transverse momentum (Q(T)) resummation of a colorless final state, e.g. Higgs production in gluon fusion or the production of a lepton pair via the Drell-Yan mechanism, in the limit where the invariant mass of the final state is much less than the center-of-mass energy, i.e. Q(2) << s. We show how the traditional resummation of logarithms of Q(T)/Q can be supplemented with the resummation of the leading logarithmic contributions at small x = Q(2)/s and we compute the necessary ingredients to perform such joint resummation
High-energy resummation at the LHC: the case of Drell-Yan processes
No full textWe first review the general framework which enables one to resum high-energy logarithms in hadronic processes, both in the evolution of parton densities and in the coefficient functions. We then present an all-order calculation in perturbative QCD of the inclusive Drell Yan and vector boson production in hadron-hadron collisions, in the limit where the centre of mass energy is much bigger than the invariant mass of the final state. Our calculation resums leading non-trivial logarithms in the ratio of these two scales. We also study the phenomenological relevance of the high-energy corrections for Drell-Yan processes at the LHC. We find that the resummation corrects the NNLO result by a few percent, for values of the invariant mass of the lepton pair below 100 GeV. Corrections to W, Z production are expected to be of the same order
QCD resummation for hadronic final states
No full textWe review the basic concepts of all-order calculations in quantum chromo-dynamics (QCD) and their application to collider phenomenology. We start by discussing the factorization properties of QCD amplitudes and cross-sections in the soft and collinear limits and their resulting all-order exponentiation. We then discuss several applications of this formalism to observables which are of great interest at particle colliders. In this context, we describe the all-order resummation of event-shape distributions, as well as observables that probe the internal structure of hadronic jets
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