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Evidence for an excess of B to D(*) Tau Nu decays

Journal Article · · Phys.Rev.Lett.109:101802,2012
Based on the full BABAR data sample, we report improved measurements of the ratios R(D{sup (*)}) = {Beta}({bar B} {yields} D{sup (*)} {tau}{sup -}{bar {nu}}{sub {tau}})/{Beta}({bar B} {yields} D{sup (*)} {ell}{sup -}{bar {nu}}{sub {ell}}), where {ell} is either e or {mu}. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D) = 0.440 {+-} 0.058 {+-} 0.042 and R(D*) = 0.332 {+-} 0.024 {+-} 0.018, which exceed the Standard Model expectations by 2.0{sigma} and 2.7{sigma}, respectively. Taken together, our results disagree with these expectations at the 3.4{sigma} level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model. We also report the observation of the decay {bar B} {yields} D{tau}{sup -} {bar {nu}}{sub {tau}}, with a significance of 6.8{sigma}.
Research Organization:
SLAC National Accelerator Laboratory (SLAC)
Sponsoring Organization:
US DOE Office of Science (DOE SC); High Energy Physics (HEP)
DOE Contract Number:
AC02-76SF00515
OSTI ID:
1043203
Report Number(s):
SLAC-PUB-15028; arXiv:1205.5442
Journal Information:
Phys.Rev.Lett.109:101802,2012, Journal Name: Phys.Rev.Lett.109:101802,2012 Journal Issue: 10 Vol. 109; ISSN 0031-9007
Country of Publication:
United States
Language:
English

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