Münster 2017 – scientific programme

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HK: Fachverband Physik der Hadronen und Kerne

HK 39: Heavy Ion Collisions and QCD Phases VIII

HK 39.3: Talk

Thursday, March 30, 2017, 14:45–15:00, F 1

Measurement of the production cross-section of electrons from heavy-flavour hadron decays in pp collisions at √s=2.76 TeV with ALICE — •Sebastian Hornung for the ALICE collaboration — GSI, Darmstadt, Germany — Heidelberg University, Germany

Measurements of heavy-flavour hadrons produced in proton-proton collisions are important to test perturbative Quantum ChromoDynamics and as a reference for measurements in heavy-ion collisions. Electrons from semileptonic decay of heavy-flavour hadrons are obtained subtracting the background from non-heavy-flavour sources from the inclusive electron spectra. Traditionally, this is done with the so-called cocktail-subtraction method based on a Monte Carlo simulation of electrons from various sources. This approach is affected by large systematic uncertainties, especially at low transverse momenta, where the main source of background are photon conversions and Dalitz decays of light neutral mesons. A data-driven method to subtract these electrons was developed in the last years, which turned out to be less affected by systematic uncertainties. Background electrons are reconstructed by pairing electrons (positrons) with tracks identified as positron (electron). The electron candidates belonging to low mass pairs are subtracted from the inclusive electron yield. The production cross-section of electrons from heavy-flavour hadron decays was measured in pp collisions at √s=2.76 TeV applying the pair-finding method. With the resulting cross-section the precision of the measurement of the nuclear modification factor at low transverse momenta was improved.