Bonn 2010 – wissenschaftliches Programm
HK 2.3: Vortrag
Montag, 15. März 2010, 17:15–17:30, HG I
Dileptons in proton-proton collisions at RHIC — •Jaakko Manninen — Institut für Theoretische Physik, Universität Giessen
We study the production of dileptons in proton-proton collisions at RHIC energies. The invariant mass spectrum of dileptons (electron-positron pairs or pairs of muons) stems from various hadronic sources. At low invariant masses (Ml+l−< 1 GeV), the spectrum is dominated by the decays of light (vector) mesons and can be modeled well by assuming a thermalized fireball fragmenting into hadrons and their resonances, which subsequently decay into lepton pairs. At larger invariant masses (1 GeV < Ml+l− < 3 GeV), the weak decays of charmed quarks are found to dominate the spectral shape. Above 3 GeV, different charmed mesons become the dominant source of dileptons, while the background consists of charm- and bottom-quark decays. We have studied the relative weights of the different sources of dileptons in proton-proton collisions and have found that the spectral shape can be very well understood as a superposition of the different above-mentioned sources. We have unfolded the relative production rates of different hadrons and provide an estimate for the total charm-production cross section.