Tübingen 2003 – wissenschaftliches Programm
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HK: Physik der Hadronen und Kerne
HK 11: Poster-Sitzung: Elektromagnetische und hadronische Proben
HK 11.29: Poster
Dienstag, 18. März 2003, 13:30–15:30, Foyer
Ground state correlations in deep inelastic scattering and Drell-Yan process — •Olena Linnyk, Stefan Leupold, and Ulrich Mosel — Institut für Theoretische Physik, Universität Gießen, Germany
We have studied ground state correlations as nonperturbative corrections to LO cross section formulae for such high energy processes as deep inelastic lepton on nucleon scattering (DIS) and Drell-Yan heavy lepton pair production.
The interaction of partons is taken into account via dressing the incoming quark lines with spectral functions. The partons are driven off shell by their interaction and nonvanishing transverse momentum.
We found that the effect of ground state interactions is particulary large in the region of small Bjorken x and momentum transferred Q2. For a quark width of the order of 200 MeV, the cross section change reaches as much as 50 % for Q2=10 GeV2. On the other hand, for the values of Q2 well above the resonance region, e.g. 200 GeV2, the effect of the initial quark off-shellnesses below 1 GeV turned to be small.
Semi-inclusiveness of Drell-Yan process opens a possibility to extract from the experimental data the information not only on the width but also on the shape of quark spectral function. And thus, the performed off-shell Drell-Yan cross section calculation allows for a better understanding of the quark and gluon interaction in the nonperturbative regime, as well as gives the test ground for various effective theories.
Work supported by DFG.