Quark Matter 2014 - XXIV International Conference on Ultrarelativistic Nucleus-Nucleus Collisions

19-24 May 2014
Europe/Zurich timezone

Dielectron measurements in pp, p-Pb and Pb-Pb collisions with ALICE at the LHC

19 May 2014, 11:20
20m

helium

Schlossgraben 1 64283 Darmstadt Germany
Contributed Talk Electromagnetic Probes

Speaker

Markus Kohler (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE))

Description

Electromagnetic probes are excellent messengers from the hot and dense medium created in ultra-relativistic heavy-ion collisions. Since leptons do not interact strongly, their spectra reflect the entire space-time evolution of a collision. The surrounding medium can lead to modifications of the dielectron production rate. To quantify modifications in heavy-ion collisions, measurements in pp collisions serve as a reference, while the analysis of p-A collisions allows to disentangle cold from hot nuclear matter effects. We present dielectron measurements with the ALICE central barrel detectors. The invariant mass distributions in the range $0 < m_{ee} < 3$ GeV/$c^{2}$ are compared to the expected hadronic sources for pp collisions at $\sqrt{s}=7$ TeV, and for p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV. The cross section of virtual direct photons measured in pp collisions is compared to predictions from NLO calculations as a function of the transverse momentum. Latest results of the analysis of Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV are presented.
On behalf of collaboration: ALICE

Primary author

Markus Kohler (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE))

 Slides