English

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

High Energy Physics - Phenomenology 2014-02-26 v4 High Energy Physics - Lattice

Abstract

We calculate, for the first time using unquenched lattice QCD form factors, the Standard Model differential branching fractions dB/dq2(BKll)dB/dq^2(B \to Kll) for l=e,μ,τl=e, \mu, \tau and compare with experimental measurements by Belle, BABAR, CDF, and LHCb. We report on B(BKll)\mathcal{B}(B \to Kll) in q2q^2 bins used by experiment and predict B(BKττ)=(1.44±0.15)107\mathcal{B}(B \to K \tau \tau) = (1.44 \pm 0.15) 10^{-7}. We also calculate the ratio of branching fractions Reμ=1.00023(63)R^\mu_e = 1.00023(63) and predict Rlτ=1.159(40)R^\tau_l = 1.159(40), for l=e,μl=e, \mu. Finally, we calculate the "flat term" in the angular distribution of the differential decay rate FHe,μ,τF_H^{e, \mu, \tau} in experimentally motivated q2q^2 bins.

Keywords

Cite

@article{arxiv.1306.0434,
  title  = {Standard Model predictions for B -> Kll with form factors from lattice QCD},
  author = {Chris Bouchard and G. Peter Lepage and Christopher Monahan and Heechang Na and Junko Shigemitsu},
  journal= {arXiv preprint arXiv:1306.0434},
  year   = {2014}
}

Comments

6 pages, 3 figures; v4 corrected error in evaluation of Wilson coefficient C9eff, resulting in <~ 1\sigma\ shift in observables; v3 matches version published in Phys. Rev. Lett; v2 updated to include comparison with most recent, and significantly more precise, results from LHCb. References updated