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.

The physics of heavy flavors is a very active area of research in experimental and theoretical high energy physics. A number of heavy flavor experiments at new or upgraded accelerators are just coming on line to address some of the most fundamental questions of particle physics, e.g. matter-anti-matter asymmetry (CP violation).The Seventh International Symposium on Heavy Flavor Physics focused primarily on the physics of bottom and charmed quarks, but there were also sessions on the top quark and the tau lepton. It presented a great opportunity to take stock of the field on the eve of the new era in heavy flavor physics which will be opened up by the next generation of experiments.

The first precision measurements on CP violation in the B system are reported. Both the BELLE and the BABAR collaboration presented, among others, results for sin 2ß with much improved accuracy. Results from the Sudbury Neutrino Observatory, SNO, also deserve to be mentioned. The convincing evidence of solar neutrino oscillations had been presented by SNO prior to the conference; a full presentation was given at the conference. An incredibly precise measurement of the anomalous magnetic moment of the muon is reported, a fresh result from the Brookhaven National Laboratory. Apart from these distinct physics highlights, there are also the first results from the new Tevatron run and from the relativistic heavy ion collider RHIC. Theorists write of our ever better understanding of the Standard Model and of what might lie beyond. Risky as it is to highlight only a couple of exciting subjects, it is merely meantto whet the appetite for further reading.

The is the most important conference on high energy physics in 1995. The speakers and the list of topics discussed are as follows:

The authors present a study of B decays into semileptonic final states containing charged and neutral D1(2420) and D*2(2460). The analysis is based on a data sample of 208 fb−1 collected at the?(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. With a simultaneous fit to four different decay chains, the semileptonic branching fractions are extracted from measurements of the mass difference?m = m(D**)-m(D) distributions. Product branching fractions are determined to be?(B → D1°l+?{sub l}) x?(D1° → D*+?−) = (2.97 ± 0.17 ± 0.17) x 10−3,?(B+ → D*2°l+?{sub l}) x?(D*2° → D{sup (*)+}?−) = (2.29 ± 0.23 ± 0.21) x 10−3,?(B° → D1−{ell}+?{sub {ell}}) x?(D1− → D*°?−) = (2.78 ± 0.24 ± 0.25) x 10−3 and?(B° → D*2−{ell}+?{sub {ell}}) x?(D*2− → D{sup (*)0}?−) = (1.77 ± 0.26 ± 0.11) x 10−3. In addition they measure the branching ratio?(D*2 → D?°)/?(D*2 → D{sup (*)}?−) = 0.62 ± 0.03 ± 0.02.