Measurement of the Branching Fraction for D8+ rarr tau+nu_tau and Extraction of the Decay Constant f_D_s

Lees, J.P. ; Poireau, V. ; Prencipe, E. ; Tisserand, V. ; /Annecy, LAPP ; Garra Tico, J. ; Grauges, E. ; /Barcelona U., ECM ; Martinelli, M. ; Palano, A. ; Pappagallo, M. ; /INFN, Bari /Bari U. ; Eigen, G. ; Stugu, B. ; Sun, L. ; /Bergen U. ; Battaglia, M. ; Brown, D.N.

关键词: DECAY;    LUMINOSITY;    MESONS;    PIONS;    PSEUDOSCALARS;    STANFORD LINEAR ACCELERATOR CENTER Experiment-HEP;    HEPEX;   

DOI  :  10.2172/981365
RP-ID  :  SLAC-PUB-14015
PID  :  OSTI ID: 981365
Others  :  Other: arXiv:1003.3063
Others  :  TRN: US1003838

学科分类：核物理和高能物理

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来源: SciTech Connect

【 摘 要 】

The branching fraction for the decay D{sub s}{sup +} {yields} {tau}{sup +}{nu}{sub {tau}} with {tau}{sup +} {yields} e{sup +}{bar {nu}}{sub {tau}}, is measured using a data sample corresponding to an integrated luminosity of 427 fb{sup -1} collected at center of mass energies near 10.58 GeV with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. In the process e{sup +}e{sup -} {yields} c{bar c} {yields} D*{sub s}{sup +} {bar D}{sub TAG}{bar K}X, the D*{sub s}{sup +} meson is reconstructed as a missing particle, and the subsequent decay D*{sub s}{sup +} {yields} D{sub s}{sup +}{gamma} yields an inclusive D{sub s}{sup +} data sample. Here {bar D}{sub TAG} refers to a fully reconstructed hadronic {bar D} decay, {bar K} is a K{sup -} or {bar K}{sup 0}, and X stands for any number of charged or neutral pions. The decay D{sub s}{sup +} {yields} K{sub S}{sup 0}K{sup +} is isolated also, and from ratio of event yields and known branching fractions, {Beta}(D{sub s}{sup +} {yields} {tau}{sup +}{nu}{sub {tau}}) = (4.5 {+-} 0.5 {+-} 0.4 {+-} 0.3)% is determined. The pseudoscalar decay constant is extracted to be f{sub D{sub s}} = (233 {+-} 13 {+-} 10 {+-} 7) MeV, where the first uncertainty is statistical, the second is systematic, and the third results from the uncertainties on the external measurements used as input to the calculation.