Correlated electron-positron pairs produced in heavy-ion collisions provide an excellent probe of the hot and dense strongly-interacting medium, i.e. the Quark-Gluon Plasma (QGP), created in such systems. They are produced at all stages of the collision without significant final-state interactions. Moreover, thermal radiation from the medium, both during the partonic and the hadronic phase, can be investigated through its internal conversion to e+e- pairs. In the intermediate mass region (1.2 – 2.8 GeV/c2), the measurement of thermal dileptons from the QGP is nevertheless challenging due to the dominant contribution from simultaneous semileptonic decays of correlated open heavy-flavour hadrons. The continuum yield in this mass region is sensitive to the energy loss of charm and beauty quarks in the QGP and further medium effects on the heavy-flavour hadron production. In order to understand the resulting modifications of the dielectron spectrum in heavy-ion collisions, a good understanding of the relevance of the various heavy-quark production mechanisms in proton-proton collisions is mandatory.
In this poster, the latest dielectron invariant-mass spectrum measured with ALICE in pp collisions at √s = 13 TeV is used to study the charm production mechanisms implemented in PYTHIA event generator. It will be shown how the relative importance of these processes can lead to model dependencies of the extracted charm cross section from a fit of the data.
|Centralised submission by Collaboration||Presenter name already specified|