Testing the Standard Model with Kaon Decays

During the last few years, new experimental and theoretical results have allowed ever more stringent tests of the Standard Model to be performed using kaon decays. This overview of recent progress includes an updated evaluation of the CKM matrix element Vus. Tests of CKM unitarity and gauge universality and lepton universality tests with Kl2 and Kl3 decays are discussed.Comment: 5 pages, 2 figures. Prepared for the proceedings of the Eleventh Conference on the Intersections of Particle and Nuclear Physics (CIPANP '12), St. Petersburg, FL, 29 May - 03 June 201

Searches for rare and forbidden kaon decays at the NA62 experiment at CERN

The decay $K^+ \to \pi^+\nu\bar{\nu}$ is highly suppressed in the Standard Model (SM), while its rate can be predicted with minimal theoretical uncertainty. The branching ratio (BR) for this decay is thus a sensitive probe of the flavor sector of the SM; its measurement, however, is a significant experimental challenge. The primary goal of the NA62 experiment is to measure ${\rm BR}(K^+ \to \pi^+\nu\bar{\nu})$ with $\sim$10% precision. This will require the observation of $10^{13}$ $K^+$ decays in the experiment's fiducial volume, as well as the use of high-performance systems for precision tracking, particle identification, and photon vetoing. These aspects of the experiment will also allow NA62 to carry out a rich program of searches for lepton flavor and/or number violating $K^+$ decays. Part of the experimental apparatus was commissioned during a technical run in 2012; installation continues and data taking is expected to begin in late 2014. The physics prospects and the status of the NA62 experiment are reviewed.Comment: LaTeX, 9 pages, 2 figures. Presented at DPF 2013, the Meeting of the American Physical Society Division of Particles and Fields, Santa Cruz, California, August 13--17, 201

Forbidden Kaon and Pion Decays in NA62

NA62, an experiment at the CERN SPS to measure the branching ratio for the decay K+ -> pi+ nu nu-bar with ~10% precision, will observe ~10^13 K+ decays in its fiducial volume, and will thus also be able to carry out a rich program to search for forbidden K+ and pi0 decays, including in particular K+ decays that violate the conservation of lepton flavor and/or number. NA62's potential performance in searches for a number of forbidden K+ and pi0 decays is discussed, with initial sensitivity estimates.Comment: 11 pages, 1 table, 6 figures, 37 refs. Prepared for the Proceedings of the 2013 Kaon Physics International Conference (KAON '13), 29 April-1 May 2013, Ann Arbor, MI, USA. v2: Minor revisions requested by refere