Heavy quark expansion for the inclusive decay $\overline{B}$ --> $\tau\overline{\nu}$X

We calculate the differential decay rate for inclusive $\bar B\to\tau\ \bar\nu\,X$ transitions to order $1/m_b^2$ in the heavy quark expansion, for both polarized and unpolarized tau leptons. We show that using a systematic $1/m_b$ expansion significantly reduces the theoretical uncertainties in the...

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Detalles Bibliográficos
Autores principales: Falk, A F, Ligeti, Z, Neubert, M, Nir, Yosef
Lenguaje:eng
Publicado: 1994
Materias:
Particle Physics - Phenomenology
Acceso en línea:https://dx.doi.org/10.1016/0370-2693(94)91206-8
http://cds.cern.ch/record/257221
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author Falk, A F
Ligeti, Z
Neubert, M
Nir, Yosef
author_facet Falk, A F
Ligeti, Z
Neubert, M
Nir, Yosef
author_sort Falk, A F
collection CERN
description We calculate the differential decay rate for inclusive $\bar B\to\tau\ \bar\nu\,X$ transitions to order $1/m_b^2$ in the heavy quark expansion, for both polarized and unpolarized tau leptons. We show that using a systematic $1/m_b$ expansion significantly reduces the theoretical uncertainties in the calculation. We obtain for the total branching ratio ${\rm BR}(\bar B\to\tau\,\bar\nu\,X)=2.30\pm 0.25\%$, and for the tau polarization $A_{\rm pol}=-0.706\pm0.006$. {}From the experimental measurement of the branching ratio at LEP, we derive the upper bound $\lo\leq 0.8\gev^2$ for one of the parameters of the heavy quark effective theory.
id cern-257221
institution Organización Europea para la Investigación Nuclear
language eng
publishDate 1994
record_format invenio
spelling cern-2572212019-09-30T06:29:59Zdoi:10.1016/0370-2693(94)91206-8http://cds.cern.ch/record/257221engFalk, A FLigeti, ZNeubert, MNir, YosefHeavy quark expansion for the inclusive decay $\overline{B}$ --> $\tau\overline{\nu}$XParticle Physics - PhenomenologyWe calculate the differential decay rate for inclusive $\bar B\to\tau\ \bar\nu\,X$ transitions to order $1/m_b^2$ in the heavy quark expansion, for both polarized and unpolarized tau leptons. We show that using a systematic $1/m_b$ expansion significantly reduces the theoretical uncertainties in the calculation. We obtain for the total branching ratio ${\rm BR}(\bar B\to\tau\,\bar\nu\,X)=2.30\pm 0.25\%$, and for the tau polarization $A_{\rm pol}=-0.706\pm0.006$. {}From the experimental measurement of the branching ratio at LEP, we derive the upper bound $\lo\leq 0.8\gev^2$ for one of the parameters of the heavy quark effective theory.hep-ph/9401226CERN-TH-7124-93JHU-TIPAC-93-31UCSD-PTH-93-43WIS-93-117oai:cds.cern.ch:2572211994
spellingShingle Particle Physics - Phenomenology
Falk, A F
Ligeti, Z
Neubert, M
Nir, Yosef
Heavy quark expansion for the inclusive decay $\overline{B}$ --> $\tau\overline{\nu}$X
title Heavy quark expansion for the inclusive decay $\overline{B}$ --> $\tau\overline{\nu}$X
title_full Heavy quark expansion for the inclusive decay $\overline{B}$ --> $\tau\overline{\nu}$X
title_fullStr Heavy quark expansion for the inclusive decay $\overline{B}$ --> $\tau\overline{\nu}$X
title_full_unstemmed Heavy quark expansion for the inclusive decay $\overline{B}$ --> $\tau\overline{\nu}$X
title_short Heavy quark expansion for the inclusive decay $\overline{B}$ --> $\tau\overline{\nu}$X
title_sort heavy quark expansion for the inclusive decay $\overline{b}$ --> $\tau\overline{\nu}$x
topic Particle Physics - Phenomenology
url https://dx.doi.org/10.1016/0370-2693(94)91206-8
http://cds.cern.ch/record/257221
work_keys_str_mv AT falkaf heavyquarkexpansionfortheinclusivedecayoverlinebtauoverlinenux
AT ligetiz heavyquarkexpansionfortheinclusivedecayoverlinebtauoverlinenux
AT neubertm heavyquarkexpansionfortheinclusivedecayoverlinebtauoverlinenux
AT niryosef heavyquarkexpansionfortheinclusivedecayoverlinebtauoverlinenux

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