Observation of CP Violation in B� ? DK� Decays

by Paolo Gandini

Overview

CP violation is a well-established phenomenon in particle physics, but until 2001 it was only observed in kaons. In the last decade, several matter-antimatter asymmetries have been observed in neutral B mesons in line with the expectations of the Standard Model of the weak interaction. Direct CP violation is also expected in the decay rates of charged B+ mesons versus that of B- mesons, though the greatest effects are present in a decay that occurs just twice in 10 million decays. Such rarity requires huge samples to study and this is exactly what the LHC, and its dedicated B-physics experiment LHCb provide. This thesis presents an analysis of the first two years of LHCb data. The author describes the first observation of the rare decay, B- → DK-, D → π-K+ and the first observation of direct CP violation in this B decay. The work constitutes essential information on the experiment’s measurement of a fundamental parameter of the theory and stands as a benchmark against which subsequent analyses of this type will be compared.

Product Details

ISBN-13:	9783319376851
Publisher:	Springer International Publishing
Publication date:	08/23/2016
Series:	Springer Theses
Edition description:	Softcover reprint of the original 1st ed. 2014
Pages:	167
Product dimensions:	6.10(w) x 9.25(h) x 0.02(d)

About the Author

Paolo Gandini is a particle physicist mainly interested in Flavour Physics. As a member of the LHCb collaboration at CERN, he completed a D.Phil in Particle Physics at the University of Oxford with a thesis on CP violation studies in charged B decays. He is currently based at CERN as a postdoctoral researcher for Syracuse University, NY.

Table of Contents

Introduction.- CP violation in the SM and the CKM angle γ.- The LHCb experiment at the LHC.- Reconstruction and selection.- Background studies.- The simultaneous fit.- Results.- Conclusions.- Distributions of the BDT input variables.- Validation of the ApT variable.- Histograms of systematic errors.- Bibliography.