Session H5: Panofsky Prize

Sunday, May 1, 2011

Experiments in the 1960's found that strangeness-changing neutral current decays, e.g. $K^0_L \rightarrow \mu^+\mu^-$, $K^+ \rightarrow \pi^+ \nu\bar{\nu}$ were suppressed by many orders of magnitude, triggering great theoretical progress including the prediction of three new, heavy quarks: charm, beauty, top. Together with huge advances in accelerators and detectors this opened up a grand new field of flavor physics in the 1980's, including precise calculations for rates of a few special rare K and B decays, and for CP-violating asymmetries. This presentation will focus broadly on the first several years of an experiment at the Brookhaven AGS (E 787), to measure the branching ratio of the extremely rare process $K^+ \rightarrow \pi^+ \nu\bar{\nu}$ with sufficient sensitivity and background rejection to cover the range predicted by the Standard Model of a few times 10$^{-10}$. It will conclude with brief remarks on similar physics at the B Factories.   

Sunday, May 1, 2011

The second stage of the E787 rare kaon decay experiment is described: how the lessons of the first round were incorporated in the upgraded beam and detector, what was discovered and what new lessons were learned. The miraculous birth, brief fluorescence, premature death, and imminent afterlife of E949 is recounted.   

Sunday, May 1, 2011

Studies of rare decays of kaons have been important in establishing the current picture of particle physics and in constraining hypothetical new approaches which go beyond the Standard Model to deal with its known deficiencies. Experimental capabilities have increased in concert with theoretical understanding making this approach to searching for new physics more viable than ever and essential, even in the era of the LHC. In this talk, I will discuss the most interesting and incisive rare kaon decay experiments, particularly $K^+\to \pi ^+\nu \bar {\nu }\mbox{ and }K_L^0 \to \pi ^0\nu \bar {\nu }$, emphasizing the prospects for major advancements in the near term and at future high intensity proton accelerators.