Transport model analysis of the transverse momentum and rapidity dependence of pion interferometry at SPS energies

Abstract

Based on the UrQMD transport model, the transverse momentum and the rapidity dependence of the Hanbury–Brown–Twiss (HBT) radii RL, RO, RS as well as the cross term ROL at SPS energies are investigated and compared with the experimental NA49 and CERES data. The rapidity dependence of RL, RO, RS is weak while ROL is significantly increased at large rapidities and small transverse momenta. The HBT ‘lifetime’ issue (the phenomenon that the calculated value is larger than the correspondingly extracted experimental data) is also present at SPS energies.