B_s->D_s/B->D Semileptonic Form-Factor Ratios and Their Application to BR(B^0_s->\mu^+\mu^-)
| Autor: | Bailey, Jon A., Bazavov, A., Bernard, C., Bouchard, C. M., DeTar, C., Du, Daping, El-Khadra, A. X., Foley, J., Freeland, E. D., Gamiz, E., Gottlieb, Steven, Heller, U. M., Kim, Jongjeong, Kronfeld, A. S., Laiho, J., Levkova, L., Mackenzie, P. B., Meurice, Y., Neil, E., Oktay, M. B., Qiu, Si-Wei, Simone, J. N., Sugar, R., Toussaint, D., Van de Water, R. S., Zhou, Ran |
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| Rok vydání: | 2012 |
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| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.85.114502 |
| Popis: | We calculate form-factor ratios between the semileptonic decays \bar{B}->D^+\ell^-\bar{\nu} and \bar{B}_s->D_s^+\ell^-\bar{\nu} with lattice QCD. These ratios are a key theoretical input in a new strategy to determine the fragmentation fractions of the neutral B decays, which are needed for measurements of BR(B^0_s-> \mu^+\mu^-). We use the MILC ensembles of gauge configurations with 2+1 flavors of sea quarks at two lattice spacings of approximately 0.12 fm and 0.09 fm. We use the model-independent z-parametrization to extrapolate our simulation results at small recoil toward maximum recoil. Our results for the form-factor ratios are $f_0^{(s)}(M^2_\pi)/f_0^{(d)}(M^2_K) =1.046(44)_{stat.}(15)_{syst.}$ and $f_0^{(s)}(M^2_\pi)/f_0^{(d)}(M^2_\pi)=1.054(47)_{stat.}(17)_{syst.}$. In contrast to a QCD sum-rule calculation, no significant departure from U-spin (d<->s) symmetry is observed. Comment: 30 pages, 11 figures. Fig. 1 updated. Table II added. Conforms with version published in Physical Review D, except typos fixed, as in the PRD Erratum, in Table V (previously Table IV in arXiv v1). Results unchanged |
| Databáze: | arXiv |
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