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

May 19, 2014, 11:20 AM
helium (darmstadtium)



Schlossgraben 1 64283 Darmstadt Germany
Contributed Talk Electromagnetic Probes Electromagnetic probes


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


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))

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