Feasibility study for the measurement of the B-meson nuclear modification factor via displaced D mesons with the ALICE detector at the LHC
Summary
The universe is believed to have been in a state of free quarks right after the big bang. This state, called a quark-gluon plasma, is subject to many studies as it teaches us about the earliest properties of the universe. The Large Hadron Collider is a particle accelerator built to simulate the quark-gluon plasma phase. Its detectors measure the properties of mesons traversing the quark-gluon plasma. Qualitative comparison of the properties of these mesons to similar mesons that have not traversed a quark-gluon plasma, provides information about the plasma.
In the near future, the LHC will run at an energy of 14 TeV. To make recommendations for this upgrade, simulations in this research have been done at an energy of 14 TeV. Simulations of proton-proton collisions have been made using event generator PYTHIA. The decay $b \rightarrow B^0 \rightarrow D^{*+} \pi \rightarrow D^0 \pi \pi \rightarrow K^- \pi \pi \pi$ is the decay focused on. Appropriate cuts are investigated based on purity and decay length of the $D^{*+}$ by comparing properties of prompt $D^{*+}$ to that of non-prompt $D^{*+}$. It is found that the purity of non-prompt $D^{*+}$ is improved to 10\% when cutting at $p_{T}=12$. The purity of non-prompt $D^{*+}$ can also be improved by making a cut at $p_{T}=6$ including a cut at a decay length of 2250 $\mu$m, conserving 10\% of the original $D^{*+}$. Recommendations for filtering kaons, which are the mesons that are actually detected by ALICE detectors, by decay length are also made.