Modelling Drell-Yan pair production in pbar-p

We predict the triple differential cross section of the unpolarized Drell-Yan process at sqrt(S)=6 GeV. The model incorporates primordial parton transverse momentum and quark off-shellness effects caused by the initial state interaction.Comment: 4 pages, AIP style, talk given at the conference LEAP'05 (Low Energy Antiproton Physics

Nuclear shadowing and in-medium properties of the rho^0

We explain the early onset of shadowing in nuclear photoabsorption within a multiple scattering approach and discuss its relation to in-medium modifications of the rho^0.Comment: 4 pages, 2 figures, to appear in the proceedings of the 9th International Conference on the Structure of Baryons, Newport News, VA, USA, 3-8 Mar 200

Ground state correlations in Deep Inelastic Scattering and the Drell-Yan process

Non-perturbative corrections to the LO cross section formulae for DIS and the Drell-Yan process were calculated. The interaction of partons was taken into account via dressing the incoming quark lines with spectral functions. We found the effect of ground state correlation in DIS to be large in the region of small Bjorken x and low momentum transfer Q. For a quark width of the order of 200 MeV, the deviation from parton model cross section reaches as much as 50% for Q^2=10 GeV^2. On the other hand, for the values of Q well above the resonance region, the effect of ISI turned out to be small in DIS, but still substantial for the triple differential Drell-Yan cross section. Our calculations show that the shape of the high mass Drell-Yan pair transverse momentum distribution is fully determined by quark off-shellness. From comparison to the resent data on the Drell-Yan cross section from NuSea collaboration, we obtained for the quark width in the nucleon the value about 200 MeV.Comment: Talk presented on "IV international conference on Perspectives in Hadronic Physics", to be published in the proceedings, 6 pages, 5 figures, uses EPJ styl

Effect of quark off-shellness in DIS and the Drell-Yan process

We study higher twist corrections to the perturbative QCD cross sections for ep deep inelastic scattering and the Drell-Yan lepton pair production in pp collision. The corrections arise due to the initial state interaction of the active quarks with the spectator partons. The effect of this interaction is calculated by dressing the incoming quark lines with phenomenological single parameter Breit-Wigner spectral functions and taking into account the full off-shell kinematics. The quark width in the proton is estimated by analyzing the data on Drell-Yan triple differential cross section from the experiment E866 at Fermilab.Comment: talk on the conference "Lepton Scattering and the Structure of Hadrons and Nuclei," Erice, 16 - 24 Sept. 2004; 2 pages, 4 figures, to be published in "Progress in Particle and Nuclear Physics

Prediction for the transverse momentum distribution of Drell-Yan dileptons at GSI-PANDA

We predict the triple differential cross section of the Drell-Yan process (pbar p -> l^+l^-X) in the kinematical regimes relevant for the upcoming PANDA experiment, using a model that accounts for quark virtuality as well as primordial transverse momentum. We find a cross section magnitude of up to 10 nb in the low mass region. A measurement with 10% accuracy is desirable in order to constrain the partonic transverse momentum dispersion and the spectral function width within +-50 MeV and to study their evolution with M and sqrt(s).Comment: 4 pages, 7 figures, RevTex; the published version: typos corrected, minor changes to the tex