Speaker
Markus Ansgar Heide
(Westfaelische Wilhelms-Universitaet Muenster (DE))
Description
Measurement of electrons from heavy-flavour hadron decays in pp and p-Pb collisions with ALICE at the LHC
Markus Heide for the ALICE Collaboration, WWU Münster
Charm and beauty quark production in hadronic collisions occurs mostly in initial parton scattering processes with high virtuality. The measurement of heavy-flavour decay electrons in pp collisions with the ALICE detector represents therefore a crucial test of pQCD predictions on heavy-flavour production. At the same time, it provides an essential reference for measurements in Pb-Pb collisions, where heavy quarks are important probes for the investigation of energy-loss mechanisms in the Quark-Gluon Plasma. The influence of cold nuclear matter effects (e.g. gluon saturation, nuclear shadowing, and the Cronin effect) on the electron spectrum can be inferred from the analysis of p-Pb collisions.
ALICE makes use of its central barrel detectors TPC, TOF, TRD, and EMCal to identify electrons at mid-rapidity. From these, background electrons from decays of light mesons and photon conversions are subtracted, based on respective preceding ALICE measurements. The resulting yield of heavy-flavour hadron decay electrons is measured down to a transverse momentum of 0.5 GeV/c. In addition, the high precision vertex reconstruction with the Inner Tracking System allows for a separate determination of the electron yield from B-meson decays, either from displaced single electrons or from secondary vertices. Alternatively, the contribution from beauty-hadron decays to the inclusive spectrum of electrons from heavy-flavour hadron decays is determined via the azimuthal angular correlation between electrons and charged hadrons. Measurements of the pT-differential electron production cross sections from inclusive heavy-flavour hadron and B-meson decays in pp collisions at √s = 2.76 and 7 TeV will be presented. Furthermore, a first look will be taken at the inclusive electron spectrum from heavy-flavour hadron decays in p-Pb collisions at √sNN = 5.02 TeV.
Author
Markus Ansgar Heide
(Westfaelische Wilhelms-Universitaet Muenster (DE))
