Measurement of the ratio of branching fractions $\mathcalB(\barB^0 \to D^*+τ^-\barν_τ)/\mathcalB(\barB^0 \to D^*+μ^-\barν_μ)$статья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 24 октября 2015 г.
Аннотация:The branching fraction ratio R(D∗)≡B(B¯¯¯0→D∗+τ−ν¯¯¯τ)/B(B¯¯¯0→D∗+μ−ν¯¯¯μ) is measured using a sample of proton-proton collision data corresponding to 3.0 fb−1 of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ−→μ−ν¯¯¯μντ. The semitauonic decay is sensitive to contributions from non-Standard-Model particles that preferentially couple to the third generation of fermions, in particular Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate B¯¯¯0 decays gives R(D∗)=0.336±0.027(stat)±0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the Standard Model.