Standard Model predictions for B → Kl +l- , B- → Kl1-l2+ and B → Kν(ν)over-bar over line using form factors from Nf=2+1+1 lattice QCD

We use HPQCD's recent lattice QCD determination of B -> K scalar, vector and tensor form factors to determine Standard Model differential branching fractions for B -> Kl (+)l(-) , B- -> Kl(1)(-)l(2)(+) and B -> K nu(nu) over bar over bar . These form factors are calculated across the full q(2) range of the decay and have smaller uncertainties than previous work, particularly at low q(2). For B -> Kl(+)l(-) we find the Standard Model branching fraction in the q(2) region below the squared J/psi mass to exceed the LHCb results, with tensions as high as 4.7 sigma for B+ -> K+mu(+)mu(-). For the high q(2) region we see 3 sigma tensions. The tensions are much reduced by applying shifts to Wilson coefficients C-9 and C-10 in the effective weak Hamiltonian, moving them away from their Standard Model values consistent with those indicated by other B phenomenology. We also update results for lepton-flavor ratios R-e(mu) and R-mu(tau) and the "flat term," FeH in the differential branching fraction for l is an element of{e; mu;tau}. Our results for the form-factor dependent contributions needed for searches for lepton-flavor violating decays B -> Kl(1)(-)l(2)(+) achieve uncertainties of 7%. We also compute the branching fraction B(B -> K nu(nu) over bar) with an uncertainty below 10%, for comparison with future experimental results.