Discrete Symmetries And Cp Violation

This book takes a fresh approach to the teaching of discrete symmetries which are central to fundamental physics: mirror symmetry, matter/anti-matter symmetry, and time reversal. It is self-contained and includes detailed discussions of relevant experiments - conveying some of the fascination and intellectual challenges of experimental physics.

This lecture note provides a tutorial review of non-Abelian discrete groups and presents applications to particle physics where discrete symmetries constitute an important principle for model building. While Abelian discrete symmetries are often imposed in order to control couplings for particle physics—particularly model building beyond the standard model—non-Abelian discrete symmetries have been applied particularly to understand the three-generation flavor structure. The non-Abelian discrete symmetries are indeed considered to be the most attractive choice for a flavor sector: Model builders have tried to derive experimental values of quark and lepton masses, mixing angles and CP phases on the assumption of non-Abelian discrete flavor symmetries of quarks and leptons, yet lepton mixing has already been intensively discussed in this context as well. Possible origins of the non-Abelian discrete symmetry for flavors are another topic of interest, as they can arise from an underlying theory, e.g., the string theory or compactification via orbifolding as geometrical symmetries such as modular symmetries, thereby providing a possible bridge between the underlying theory and corresponding low-energy sector of particle physics. The book offers explicit introduction to the group theoretical aspects of many concrete groups, and readers learn how to derive conjugacy classes, characters, representations, tensor products, and automorphisms for these groups (with a finite number) when algebraic relations are given, thereby enabling readers to apply this to other groups of interest. Further, CP symmetry and modular symmetry are also presented.

The violation of charge-conjugation and parity symmetries is a leading area of research in particle and nuclear physics, with important implications for understanding the generation of matter in the universe. This book provides a self-contained introduction and is designed to bring beginning researchers to the forefront of the field.

Description of experiments that uncovered the nature of CP violation and the phenomenology describing CP violation. The author Konrad Kleinknecht received the Leibniz award of the Deutsche Forschungsgemeinschaft 1990 and the Gentner-Kastler prize and medal of SFP and DPG 2001.

Electric dipole moments (EDMs) have interested physicists since 1950, when it was first suggested that there was no experimental evidence that nuclear forces are symmetric under parity (P) transformation. This question was regarded as speculative because the existence of an EDM, in addition to P violation, requires a violation of time-reversal (T) symmetry. In 1964 it was discovered that the invariance under CP transformation, which combines charge conjugation (C) with parity, is violated in K-meson decays. This provided a new incentive for EDM searches. Since the combined operations of CPT are expected to leave a system invariant, breakdown of CP invariance should be accompanied by a violation of time-reversal symmetry. Thus there is a reason to expect that EDMs should exist at some level. The original neutron EDM experiments were later supplemented with checks of T invariance in atoms and molecules. These investigations are pursued now by many groups. Over the years, the upper limit on the neutron EDM has been improved by seven orders of magnitude, and the upper limit on the electron EDM obtained in atomic experiments is even more strict.

CP violation is one of the most subtle effects in the Standard Model of particle physics and may be the first clue to the physics that lies beyond. Charge conjugation, C, and parity, P, are symmetries of particle interactions. C corresponds to the operation of replacing a particle by its antiparticle, while P is the operation of mirror reflection. Before 1956, it was believed that these were also symmetries of the interactions of elementary particles. In 1956, C S Wu found evidence for P violation in the weak interaction. Theorists proposed that the combination of CP would be a symmetry of the weak interaction. In 1964, Christenson, Cronin, Fitch and Turlay found the first evidence for the violation of CP symmetry in the decays of kaons.Although Kobayashi and Maskawa then showed how the Standard Model can accommodate the observed CP violation, Wolfenstein pointed out that it is also possible that there is a new interaction in addition to the usual four, called the superweak interaction, which is responsible for the asymmetry. To test this idea, the observation of a different type of asymmetry, called direct CP violation, is required; in the kaon sector, very precise measurements of the ratio of kaon decay rates are necessary. In B decay modes where a second order weak process whimisically named “penguin” interferes with another suppressed, first order “tree” amplitude, it may also be possible to observe these direct CP-violating effects.B physics and CP violation is now one of the major growth areas in high energy physics. Nearly every major high energy physics laboratory now has a project underway to observe the large CP asymmetries expected in the B sector and to test the consistency of the Standard Model. The unitarity of the Kobayashi-Maskawa mixing matrix in the Standard Model implies the existence of three phases, called alpha, beta and gamma, which can be determined by the measurements of CP asymmetries in B decays. About 200 participants gathered in Hawaii in March 1997 to discuss the progress in the field, and this important book constitutes the proceedings of that conference.

http://www.worldscientific.com/worldscibooks/10.1142/0496

This book presents the proceedings of The International Workshop on Frontiers in High Energy Physics (FHEP 2019), held in Hyderabad, India. It highlights recent, exciting experimental findings from LHC, KEK, LIGO and several other facilities, and discusses new ideas for the unified treatment of cosmology and particle physics and in the light of new observations, which could pave the way for a better understanding of the universe we live in. As such, the book provides a platform to foster collaboration in order to provide insights into this important field of physics.