1.
Phys Rev Lett
; 115(7): 071801, 2015 Aug 14.
Article
in English
| MEDLINE
| ID: mdl-26317713
ABSTRACT
A new measurement of the branching ratio R_{e/µ}=Γ(π^{+}âe^{+}ν+π^{+}âe^{+}νγ)/Γ(π^{+}âµ^{+}ν+π^{+}âµ^{+}νγ) resulted in R_{e/µ}^{exp}=[1.2344±0.0023(stat)±0.0019(syst)]×10^{-4}. This is in agreement with the standard model prediction and improves the test of electron-muon universality to the level of 0.1%.
