On lepton pair production in proton-antiproton collisions at intermediate energies

Abstract

The lepton pair production via the quark-antiquark annihilation subprocess in collisions of beam antiproton with the proton target at E beam = 14 GeV is studied on the basis of the event sample simulated by PYTHIA6 generator. Different kinematical variables which may be useful for the design of the muon system and the electromagnetic calorimeter of the detector of PANDA experiment at FAIR, as well as for the study of proton structure functions in the available x-Q 2 kinematical region, are considered. It is also argued that the measurement of the total transverse momentum of a lepton-antilepton system may provide important information about the intrinsic transverse momentum 〈k T 〉 that appears due to the Fermi motion of quarks inside the nucleon. Another interesting possibility is the measurement of the production rate of two or three lepton pairs in one event that can give the information about the rate of multiple quarks interactions and the proton space structure. The problems due to the presence of fake leptons that appear from meson decays, as well as due to the contribution of background QCD processes and minimum bias events, are also discussed. The set of cuts which allows one to separate the events with the signal lepton pairs from different kind of background events is proposed.