Azimuthal angular correlations between charged D* mesons and hadrons in proton-proton collisions at sqrt(s) = 7 TeV in ALICE

Abstract

The Quark Gluon Plasma (QGP) is a state of matter that is postulated in a quark model of Hadrons, Quantum Chromodynamics. The behaviour of the QGP is studied at the Large Hadron Collider in Geneva, Switzerland. Charmed mesons are used as probes for the QGP, these mesons are D mesons. In this thesis the D$^{*+}$ meson was studied, which can be reconstructed using different subdetectors (ITS, TPC and TOF) in the ALICE experiment.

In this thesis the azimuthal angular correlations in the $\Delta \phi$ coordinates are studied. Azimuthal angular correlations are studied in order to learn more about the energy loss mechanism of the QGP, what happens to the recoil heavy quark in association with the one studied and to learn what happens to the jet fragmentation of heavy quarks modified by the interaction with the medium.

The yield and sigma for the near-side peak are extracted from the azimuthal distributions. The away-side peak is not studied because of low statistics. The yield shows the expected behaviour, where it increases with increasing transverse momentum (p$_{\rm{T}}$) ranges. The behaviour of the sigma is difficult to conclude from the results. The systematic error is studied by varying the cut on the minimum number of TPC clusters.

Since this is a new study my work has mostly been contributing to the code and obtaining the first results.