2026-04-19T13:28:23Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1317762025-11-21T05:47:04Zcom_2072_1057col_2072_478823col_2072_478917

urn:hdl:2445/131776 Measurement of an excess of ¯B → D(*)τ−¯ντ decays and implications for charged Higgs bosons Graugés Pous, Eugeni BABAR Collaboration Física de partícules Experiments Bosons de Higgs Particle physics Experiments Higgs bosons Based on the full BABAR data sample, we report improved measurements of the ratios R ( D ) = B ( ¯¯¯ B → D τ − ¯ ν τ ) / B ( ¯¯¯ B → D ℓ − ¯ ν ℓ ) and R ( D ∗ ) = B ( ¯¯¯ B → D ∗ τ − ¯ ν τ ) / B ( ¯¯¯ B → D ∗ ℓ − ¯ ν ℓ ) , where ℓ refers to either an electron or muon. 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 σ and 2.7 σ , respectively. Taken together, the results disagree with these expectations at the 3.4 σ level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model. Kinematic distributions presented here exclude large portions of the more general type III two-Higgs-doublet model, but there are solutions within this model compatible with the results. 2019-04-08T11:25:16Z 2019-04-08T11:25:16Z 2013-10-31 2019-04-08T11:25:16Z info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Reproducció del document publicat a: https://doi.org/10.1103/PhysRevD.88.072012 Physical Review D, 2013, vol. 88, num. 7, p. 072012 https://doi.org/10.1103/PhysRevD.88.072012 (c) American Physical Society, 2013 info:eu-repo/semantics/openAccess American Physical Society Articles publicats en revistes (Física Quàntica i Astrofísica)