New studies of allowed pion and muon decays
Abstract
Building on the rare pion and muon decay results of the PIBETA experiment, the PEN collaboration has undertaken a precise measurement of B_{\pi e2} = R^\pi_{e/\mu}, the \pi^+ -> e^+\nu(\gamma) decay branching ratio, at the Paul Scherrer Institute, to reduce the present 40\times experimental precision lag behind theory to ~ 6-7\times. Because of large helicity suppression, R^\pi_{e/\mu} is uniquely sensitive to contributions from non-(V-A) physics, making this decay a particularly suitable subject of study. Even at current precision, the experimental value of B_{\pi e2} provides the most accurate test of lepton universality available. During runs in 2008-10, PEN has accumulated over 2\times 10^7 \pi_{e2} events; a comprehensive maximum-likelihood analysis is currently under way. The new data will also lead to improved precision of the earlier PIBETA results on radiative \pi and \mu decays.
Keywords
Cite
@article{arxiv.1210.5025,
title = {New studies of allowed pion and muon decays},
author = {D. Pocanic and A. Palladino and L. P. Alonzi and V. A. Baranov and W. Bertl and M. Bychkov and Yu. M. Bystritsky and E. Frlez and V. A. Kalinnikov and N. V. Khomutov and A. S. Korenchenko and S. M. Korenchenko and M. Korolija and T. Kozlowski and N. P. Kravchuk and N. A. Kuchinsky and M. C. Lehman and D. Mekterovic and E. Munyangabe and D. Mzhavia and P. Robmann and A. M. Rozhdestvensky and S. N. Shkarovskiy and U. Straumann and I. Supek and P. Truöl and Z. Tsamalaidze and A. van der Schaaf and E. P. Velicheva and V. P. Volnykh},
journal= {arXiv preprint arXiv:1210.5025},
year = {2015}
}
Comments
3 pages, 3 figures, to appear in Proceedings, 11th Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2012), held at St. Petersburg, Florida, 29 May - 3 June 2012