Searching for CP Violation in Pion Decay.pdf

IIT-HEP-98/4 September 1998 SEARCHING FOR CP VIOLATION IN PION DECAYa 8 9 9 DANIEL M. KAPLAN 1 Physics, Illinois Institute of Technology, p Chicago, IL 60616, USA e E-mail: kaplan@fnal.gov S 5 Abstract 1 Surprisingly, until recently CP violation in pion decay was not ruled out experimentally even at the percent level. I have derived the first ex- 1 v perimental limit, −0.01 ACP 0.02, from old data on the anomalous 0 magnetic moment g − 2 of the muon. New data from the Brookhaven 0 g − 2 experiment might extend the search by a few orders of magni- 4 tude, but probably will not probe the theoretically-interesting sub-10−7 9 regime. 0 8 9 1 Introduction / h While the main topic of this Workshop is CP violation in heavy-quark systems p (s, c, b, and even t have been discussed), it is perhaps surprising to realize that - p we don’t even know whether pion decay conserves CP ! If we consider this e question, we are likely to assume that the answer is yes, but an experimental h test would be desirable. : v i X 2 A Possible CP -Violation Signatur