Bonn 2010 – wissenschaftliches Programm
HK 64.4: Vortrag
Freitag, 19. März 2010, 15:00–15:15, HG III
Partonic offshell effects in next-to-leading order Drell-Yan processes at PANDA energies — •Fabian Eichstädt1, Stefan Leupold1,2, and Ulrich Mosel1 — 1Institut für Theoretische Physik, Universität Giessen — 2Department of Physics and Astronomy, Uppsala University, Sweden
We investigate the effects of quark distributions of intrinsic transverse momentum and mass on the unpolarised production of Drell-Yan (DY) pairs. The standard leading-order parton model description has shortcomings: a K-factor is necessary to describe invariant mass spectra and no transverse momentum pT is generated in this scheme . In addition, e.g., PANDA at FAIR will measure at comparatively low hadron centre-of-mass energies of √s ≈ 5.5 GeV . Therefore non-pertubative effects are expected to play an important role. To address these issues we study a QCD-inspired phenomenological parton model which includes leading-order  and next-to-leading-order (NLO) production processes. We introduce mass distributions for the quarks to handle the divergencies of the NLO processes at pT → 0. Finally, fixing our phenomenological distributions at available data, our aim is to predict DY pair production at PANDA.
Supported by HIC for FAIR and GSI.
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