Monte-Carlo simulation of lepton pairs production in 'p p-bar → μ+μ− + X' events at Ebeam = 5 GeV

Muon pairs production via the quark-antiquark annihilation process in collisions of antiproton beam with Ebeam = 5 GeV (which corresponds to the center-of-mass energy of the p p-bar system Ecm = 3.363 GeV) with the proton target in PANDA experiment is modeled by using of PYTHIA6.4 generator. The considered quark level subprocess goes through the production of virtual photon which converts into lepton pair (q q-bar → γ* → μ+μ−). Quark-antiquark annihilation process of hadron-hadron collision may provide an interesting information about the quark dynamics inside the hadron. The measurement of the total transverse momentum of a lepton pair as a whole system may provide an important information about the intrinsic transverse momentum kT that appears due to the Fermi motion of quarks inside the nucleon. The distributions of different kinematical variables of final state muons are presented. The problems due to the presence of fake leptons that appear from meson decays, as well as due to the background caused by minimum bias events are also discussed. The set of cuts which allows to separate the signal events with lepton pairs from the backgrounds is proposed.