Experimental Tests of Lepton Universality in Tau Decay from CLEO
نویسنده
چکیده
The branching fractions for !ee, , and hh are measured using data collected with the, where the rst errors are statistical, the second systematic, and h refers either to a charged or K. Also measured is the tau mass, m=(1778.21.4) MeV. Lepton universality is aarmed by the resulting relative branching fractions (B/Be=0.97770.00630.0087, B h /Be=0.64840.00410.0060) and the charged-current gauge coupling-constant ratios (g=ge=1.00260.0055, g=g=0.99900.0098). The tau mass result may be recast as a tau neutrino mass limit, m <60 MeV at 95% CL.
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