The probability of occurrence (branching fraction) of the yet-unobserved decay of Bs mesons into two muons is currently considered as one of the most stringent tests for the existence of physics beyond the Standard Model (SM) of particle physics. There exists indeed a large unexplored range between the current experimental upper limit and the SM prediction about this branching fraction, making a measurement incompatible with the SM possible. Furthermore, there exist predictions for this branching fraction in the frame of numerous theoretical models that aim at a more accurate description of matter than that offered by the Standard Model. Some of those predictions significantly differ from the SM one, opening the possibility of an indirect discovery of New Physics. LHCb is the CERN experiment primarily dedicated to the study of the quark b. This book addresses the sensitivity of the LHCb experiment to this branching fraction using Monte-Carlo simulations. It is shown that LHCb will compete with the current exclusion limit of the Bs to mu mu branching fraction already with the data recorded in 2010.

This book discusses the study of double charm B decays and the first observation of B0->D0D0Kst0 decay using Run I data from the LHCb experiment. It also describes in detail the upgrade for the Run III of the LHCb tracking system and the trigger and tracking strategy for the LHCb upgrade, as well as the development and performance studies of a novel standalone tracking algorithm for the scintillating fibre tracker that will be used for the LHCb upgrade. This algorithm alone allows the LHCb upgrade physics program to achieve incredibly high sensitivity to decays containing long-lived particles as final states as well as to boost the physics capabilities for the reconstruction of low momentum particles.

This book presents the latest results on the branching fraction and phase space distribution of B0 and Bs0 decays into final states including excited neutral charm mesons. This work represents four years of research, and the book describes in detail all the necessary steps and techniques required to perform a physics analysis of the data recorded by the LHCb experiment in the years 2016–2018. Although the results presented in this book represent the first measurement of such decays, the text is written in a manner accessible to Ph.D. students and early career researchers. Thus, all the contents included in this book are described in a pedagogical way, including technical details that would allow the results to be reproduced in future. In addition to the methodology used to perform these measurements, the book also includes a description of the theoretical background required to interpret the results presented, as well as a technical description of the LHCb detector, which provided the data sample used in this study.