Investigating violations of some fundamental symmetries of nature via Dalitz plots and Dalitz prisms [HBNI Th88]

Abstract

In this thesis we are concerned with violations of some fundamental symmetries in the realm of elementary particles, namely, Bose symmetry, the combined operations of charge conjugation and parity (and time-reversal), and the SU(3) flavor symmetry. These four symmetries influence various elementary particle processes. So by studying some specific particle processes one can look for signatures of violations of these symmetries. The thesis is divided into five parts. Part I introduces the relevant background materials in two chapters. Chapter 1 provides a very concise introduction to the concept of symmetry as applied to physical laws and also introduces very briefly the symmetries of interest to this thesis, namely the Bose symmetry, CP and CPT symmetries and the flavor SU(3) symmetry. Chapter 2 gives a concise description of the concept of Dalitz plot and finally introduces the kind of Dalitz plot that would be useful in our study of the violations of the symmetries. Part II gives in detail all the original findings of this thesis in two chapters. Chapter 3 generalizes the concept of Dalitz plot to a three-dimensional plot, christened as Dalitz prism, which not only handles resonant three-body decays but also continuum production of three final particles and multi-body processes which can be treated as “effective” threebody processes. Thus, it works as a precision tool for looking at minute violations of symmetry, as it is rich with data by construction. In Chapter 4 we analyze in detail the signatures of all the symmetry violations under consideration in Dalitz plots and Dalitz prisms. Here various relevant Dalitz plot asymmetries are provided which would quantify the extent of breaking of our chosen symmetries. Part III contains Chapter 5 which succinctly summarizes the research findings of Part II. This is followed by Part IV which contains the appendices. Appendix A describes in some detail a few concepts in flavor SU(3) symmetry including introduction of two new G-parities. Appendix B summarizes the concept of ternary plot which is used in Chapter 2 to develop the Dalitz plot that would be helpful in Chapter 4. Finally Part V lists all the references and provides an index.