Based on the full BABAR data sample, we report improved measurements of the ratios R(D)=B(B¯→Dτ-ν¯τ)/B(B¯→Dℓ-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 2.0σ and 2.7σ, respectively. Taken together, the results disagree with these expectations at the 3.4σ 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.
Measurement of an excess of B ¯→D(*)τ-ν¯_τ decays and implications for charged Higgs bosons
BIANCHI, Fabrizio;DE MORI, FRANCESCA;GAMBA, Diego;
2013-01-01
Abstract
Based on the full BABAR data sample, we report improved measurements of the ratios R(D)=B(B¯→Dτ-ν¯τ)/B(B¯→Dℓ-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 2.0σ and 2.7σ, respectively. Taken together, the results disagree with these expectations at the 3.4σ 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.File | Dimensione | Formato | |
---|---|---|---|
PhysRevD.88.072012(2).pdf
Accesso aperto
Tipo di file:
PDF EDITORIALE
Dimensione
4.22 MB
Formato
Adobe PDF
|
4.22 MB | Adobe PDF | Visualizza/Apri |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.