|
|||||
|
|
Precise measurement of the pi+-->pi0 e+nu branching ratio |
|
| Authors: | Pocani? D Frlez E Baranov V A Bertl W Brönnimann Ch Bychkov M Crawford J F Daum M Khomutov N V Korenchenko A S Korenchenko S M Kozlowski T Kravchuk N P Kuchinsky N A Li W Minehart R C Mzhavia D Ritchie B G Ritt S Rozhdestvensky A M Sidorkin V V Smith L C Supek I Tsamalaidze Z VanDevender B A Wang Y Wirtz H-P Ziock K O H |
| Institution: | Department of Physics, University of Virginia, Charlottesville, VA 22904-4714, USA. pocanic@virginia.edu |
| Abstract: | Using a large acceptance calorimeter and a stopped pion beam we have made a precise measurement of the rare pi(+)-->pi(0)e(+)nu (pi(beta)) decay branching ratio. We have evaluated the branching ratio by normalizing the number of observed pi(beta) decays to the number of observed pi(+)-->e(+)nu (pi(e2)) decays. We find the value of Gamma(pi(+)-->pi(0)e(+)nu)/Gamma(total)=1.036+/-0.004(stat)+/-0.004(syst)+/-0.003(pi(e2))]x10(-8), where the first uncertainty is statistical, the second systematic, and the third is the pi(e2) branching ratio uncertainty. Our result agrees well with the standard model prediction. |
| Keywords: | |
| 本文献已被 PubMed 等数据库收录！ | |