6533b7d4fe1ef96bd1263321

RESEARCH PRODUCT

Dynamical threshold enhancement and resummation in Drell-Yan production

Gang XuMatthias NeubertMatthias NeubertMatthias NeubertThomas Becher

subject

PhysicsNuclear and High Energy PhysicsParticle physics010308 nuclear & particles physicsNuclear TheoryHigh Energy Physics::PhenomenologyHadronFOS: Physical sciencesPosition and momentum spaceParton01 natural sciences7. Clean energyHigh Energy Physics - PhenomenologyCross section (physics)High Energy Physics - Phenomenology (hep-ph)0103 physical sciencesEffective field theoryHigh Energy Physics::ExperimentRapidityInvariant massResummationNuclear Experiment010306 general physics

description

Partonic cross sections for the production of massive objects in hadronic collisions receive large corrections when the invariant mass of the initial-state partons is just above the production threshold. Since typically the center-of-mass energy of the hadronic collision is much higher than the mass of the heavy objects, it is not obvious that these contributions translate into large corrections to the hadronic cross section. Using a recent approach to threshold resummation based on effective field theory, we quantify to which extent the fall-off of the parton densities at high x leads to a dynamical enhancement of the partonic threshold region. With the example of Drell-Yan production, we study the emergence of an effective physical scale characterizing the soft emissions in the process. We derive compact analytical expressions for the resummed Drell-Yan cross section and rapidity distribution directly in momentum space. They are free of Landau-pole singularities and are trivially matched onto fixed-order perturbative calculations. Evaluating the resummed cross sections at NNNLL order and matching onto NNLO fixed-order calculations, we perform a detailed numerical analysis of the cross section and rapidity distribution in proton-proton collisions.

https://doi.org/10.1088/1126-6708/2008/07/030