Alves, G.A
Tau production
TANBETA/MC=HIGGS+-
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Measurement of the branching ratio for the process b --> tau- anti-nu/tau X.

The OPAL collaboration Abbiendi, G. ; Ainsley, C. ; Åkesson, P.F. ; et al.
Phys.Lett.B 520 (2001) 1-10, 2001.
Inspire Record 561580 DOI 10.17182/hepdata.49743

The inclusive branching ratio for the process b -> tau nu X has been measured using hadronic Z decays collected by the OPAL experiment at LEP in the years 1992-2000. The result is: BR(b -> tau nu X) = (2.78 +/- 0.18 +/- 0.51)% This measurement is consistent with the Standard Model expectation and puts a constraint of tan(beta) / M(H+/-) < 0.53 GeV-1 at the 95% confidence level on Type II Two Higgs Doublet Models.

1 data table
Table 1

TAN(BETA) is the two-Higgs-doublet model parameter, while M_H is the mass of charged Higgs.


Measurements of BR(b --> tau- anti-nu/tau X) and BR(b --> tau- anti-nu/tau D*+- X) and upper limits on BR(B- --> tau- anti-nu/tau) and BR(b --> s nu anti-nu).

The ALEPH collaboration Barate, R. ; Decamp, D. ; Ghez, Philippe ; et al.
Eur.Phys.J.C 19 (2001) 213-227, 2001.
Inspire Record 534887 DOI 10.17182/hepdata.49822

Inclusive branching ratios involving b to tau transitions are measured in approximately four million hadronic Z decays collected by the ALEPH detector at LEP. The fully-inclusive branching ratio b -> tau nu X and the semi-inclusive branching ratio b -> tau nu D*+/- X are measured to be (2.43 +/- 0.20 +/- 0.25)% and (0.88 +/- 0.31 +/- 0.28)%, in agreement with the standard model predictions. Upper limits on the branching fractions b -> tau nu and b -> s nu nubar are set to 8.3 10**-4 and 6.4 10**-4 at the 90% C.L. These results allow a 90% C.L. lower limit of 0.40 (GeV/c**2)**-1 to be set on the tan(beta)/mH+/- ratio, in the framework of type-II two-Higgs-doublet mode

1 data table
Table 1

TAN(BETA) is the two-Higgs-doublet model parameter, while M_H is the mass of charged Higgs.


Upper limit for the decay B- ---> tau- anti-neutrino (tau) and measurement of the b ---> tau anti-neutrino (tau) X branching ratio

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 496 (2000) 43-58, 2000.
Inspire Record 511452 DOI 10.17182/hepdata.49004

The branching ratio for the leptonic decay of charged B mesons ( B − →τ − ν ̄ τ ) has been measured using selected leptonic τ − →ℓ − ν τ ν ̄ ℓ and hadronic τ − → ν τ X decays in Z → b b ̄ decays recorded by DELPHI at LEP1 in 1992–1995. The result, BR ( B − →τ − ν ̄ τ )<1.1×10 −3 at the 90% confidence level, is consistent with standard model expectations and puts a constraint on the ratio tan β / M H ± <0.46 (GeV/ c 2 ) −1 in the framework of models with two Higgs doublets (type II Higgs doublet model). From the missing energy distribution in Z → b b ̄ decays without identified leptons, the b →τ ν ̄ τ X branching ratio has been measured in the hadronic channel τ → ν τ X′. The result, BR ( b →τ ν ̄ τ X )=(2.19±0.24 ( stat )±0.39 ( syst ))% , is consistent with the Standard Model prediction and with previous experimental measurements.

1 data table
Table 1

TAN(BETA) is the two-Higgs-doublet model parameter, while M_H is the mass of charged Higgs.