| dc.description.abstract | The Quark-Gluon Plasma is a state of matter that is expected to form at high temperatures and densities. Therefore, it is expected to be produced in lead-lead ion collisions in ALICE at CERN. Jets, consisting of fragments of the heavy quarks produced during these collisions, can be used to study this medium. Specifically, jets containing D^0-mesons are considered.
The aim of this study is to assess the systematic uncertainty in the charm jet transverse momentum distribution in lead-lead ion collisions at \sqrt{s_{NN}}=2.76 TeV. Two procedures, called the purple and orange to distinguish them, are developed and described thoroughly. In both cases, the jet transverse momentum distribution is determined using information from the invariant mass distribution of kaon pion pairs. The main difference between the two procedures is the moment of correction for the efficiency due to selection cuts and detector effects.
The procedures are applied to obtain the jet transverse momentum distribution for four different sets of selection cuts. Additional cuts in D^0-meson transverse momentum were needed in the purple procedure to remove background influence and improve the jet transverse momentum distribution. The same cuts were applied in the orange procedure. Subsequently, the distributions are studied and compared.
The obtained jet transverse momentum distribution for all four selection cut sets are not consistent for both procedures. The distributions for the four sets resulting from the orange procedure do have similar shapes. The systematic uncertainty is in the order of 10^{-3} (GeV/c)^{-1}.
The obtained results from the orange and purple procedure are also compared to each other. The jet transverse momentum distributions are not consistent; the systematic uncertainty depends on the selection cut set used.
Further examination of the purple procedure is recommended, since fluctuations, enhanced by the correction for efficiency, play an important role. | |
