Strange quark mass from the invariant mass distribution of Cabibbo-suppressed tau decays

S. Chen; M. Davier; E. Gámiz; A. Höcker; A. Pich; J. Prades

doi:doi:10.1007/s100520100791

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2024 Impact factor 4.8

Particles and Fields

Eur. Phys. J. C 22, 31-38 (2001)
DOI: 10.1007/s1005201O0791

Strange quark mass from the invariant mass distribution of Cabibbo-suppressed tau decays

S. Chen¹, M. Davier¹, E. Gámiz², A. Höcker¹, A. Pich³ and J. Prades²

¹ Laboratoire de l'Accélérateur Linéaire, Université de Paris-Sud, IN2P3-CNRS, 91898 Orsay Cedex, France
² Departamento de Física Teórica y del Cosmos, Universidad de Granada, Campus de Fuente Nueva, 18002 Granada, Spain
³ Departament de Física Teòrica, IFIC, Universitat de València - CSIC, Edifici d'Instituts de Paterna, Apt. Correus 22085, 46071 València, Spain

(Received: 22 May 2001 / Published online: 5 November 2001 - © Springer-Verlag / Societá Italiana di Fisica 2001)

Abstract
Quark mass corrections to the $\tau$ hadronic width play a significant role only for the strange quark. The complete determination of $\tau$ decays into strange hadronic final states performed by ALEPH allows the extraction of the strange spectral function. New results on strange decay modes from other experiments are also incorporated into the present analysis. Using as input moments of the spectral function the analysis leading to the determination of m_s is conducted using reasonable theoretical constraints on the nonperturbative components. Careful attention is paid to the treatment of the perturbative expansions of the moments which exhibit convergence problems. The result obtained, $m_s(M_\tau^2)=(120\pm11_{\rm exp}\pm8_{V_{us}}\pm 19_{\rm th})~{\rm MeV} = (120^{\,+21}_{\,-26})~{\rm MeV}$ , is stable over the scale from $M_\tau^2$ down to about 2 GeV ². Its evolution yields $m_s(1~{\rm GeV}^2) = (160^{\,+28}_{\,-35})~{\rm MeV}$ and $m_s(4~{\rm GeV}^2) = (116^{\,+20}_{\,-25})~{\rm MeV}$ .