Precise Measurement of pi+ -> e+ nu Branching Ratio

Authors :: Frlež, E.
Alonzi, L. P.
Baranov, V. A.
Bertl, W.
Bychkov, M.
Bystritsky, Yu. M.
Khomutov, N. V.
Korenchenko, A. S.
Korenchenko, S. M.
Korolija, M.
Kozlowski, T.
Kravchuk, N. P.
Kuchinsky, N. A.
Mekterović, D.
Mzhavia, D.
Palladino, A.
Počanić, D.
Robmann, P.
Rozhdestvensky, A. M.
Sidorkin, V. V.
Straumann, U.
Supek, I.
Truöl, P.
van der Schaaf, A.
Velicheva, E. P.
Volnykh, V. P.
Publication Year :: 2008
Abstract: The PEN Collaboration is conducting a new measurement of the pi+ -> e+ nu branching ratio at the Paul Scherrer Institute, with the goal uncertainty of delta B/B(pie2)=5E-4 or lower. At present, the combined accuracy of all published pie2 decay measurements lags behind the theoretical calculation by a factor of 40. In this contribution we report on the PEN detector configuration and its performance during two development runs done in 2007 and 2008.<br />Comment: pdflatex, 11 pages, 5 figures, to be published in "Progress in High-Energy Physics and Nuclear Safety", NATO Science for Peace Series: B - Physics and Biophysics