Direct $CP$ Violation in a Variety of $B$ Decays

Abstract

We give a brief review of direct $CP$ violation effects in charmless $B$ decays, both at the inclusive and at the exclusive level. It is emphasized that typical exclusive final states are composed of 2--4 $K$ or $\pi$'s, hence particle identification (in terms of $K/\pi$ separation) is of crucial importance for studying $CP$ violation in these modes. Another kind of ``charmless" final state is also emphasized: $b\to dc\bar{c}$. The decay rate is tree dominant, while ``$q^2$" is necessarily above $c\bar{c}$ threshold hence in the domain of perturbative QCD. The $CP$ asymmetry is therefore relatively clean and reliable. Theoretically, a few $\times 10^7$ $B$'s would suffice if one could accumulate modes like $B^{+}\to D^{+\left(\ast \right)}{\bar{D}}^{0\left(\ast \right)}$. [To appear in proceedings of ``The Third KEK Topical Conference on CP Violation --- Its Implications to Particle Physics and Cosmology'', 16--18 November, 1993, KEK, Tsukuba, Japan (Eds. Y. Kuno and Y. Okada).]

Comments: 7 pages, LaTeX (requires espcrc2.sty, contact: crc@elsevier.nl), NTUTH--94--05