1306.0434 (Chris Bouchard et al.)

Standard Model predictions for B -> Kll with form factors from lattice
QCD    [PDF]

Chris Bouchard, G. Peter Lepage, Christopher Monahan, Heechang Na, Junko Shigemitsu

We calculate, for the first time using unquenched lattice QCD form factors, the Standard Model differential branching fractions dB/dq^2(B -> Kll) for l=e, \mu, \tau\ and compare with experimental measurements by Belle, BABAR, CDF, and LHCb. We report on B(B -> Kll) in q^2 bins used by experiment and predict B(B -> K \tau \tau) = (1.41 \pm 0.15) 10^{-7}. We also calculate the ratio of branching fractions R^\mu_e = 1.00029(69) and predict R^\tau_l = 1.176(40), for l=e, \mu. Finally, we calculate the "flat term" in the angular distribution of the differential decay rate F_H^{e, \mu, \tau} in experimentally motivated q^2 bins.

View original: http://arxiv.org/abs/1306.0434