Probing quark-gluon plasma with beauty quarks

Abstract

This thesis presents the first ever attempts of direct measurements of B mesons in heavy ion collisions with the CMS experiment. The full decay chains of B mesons were reconstructed by identifying the corresponding decay vertices. Machine learning classification models were used extensively and an unprecedented signal to background ratio was reached. Both cross sections and nuclear modification factors which quantify the medium effect of the quark-gluon plasma were measured. This thesis will introduce the techniques that enabled these novel analyses and discuss the implications of the results.