Model-independent analysis of B -> pi l(+)l(-) Decays

作者：Ali A^*; Parkhomenko A Ya; Rusov A V

来源：Physics of Atomic Nuclei, 2015, 78(3): 436-439.

DOI：10.1134/S1063778815020064

The results obtained by calculating, on the basis of the Standard Model, the branching fractions for the decays B -> pi a"" (+) a"" (-) (a"" (+/-) = e (+/-), A mu(+/-)) and the invariant-mass spectrum of dileptons for the process B (+) -> pi (+) a"" (+) a"" (-) are presented. The resulting theoretical estimates depend on the choice of model for the B -> pi transition form factors f (+)(q (2)), f (0)(q (2)), and f (T) (q (2)). However, one can get rid of this arbitrariness by employing experimental data or the results of QCD lattice calculations to determine the parameter dependence of the form factors. Data from B-meson factories were used to determine the dependence of the form factor f (+)(q (2)) on the transfer momentum squared. Yet another required form factor, f (T) (q (2)), was extracted from available lattice data on B -> pi and B -> K transitions with allowance for nearly identical effects of the breakdown of flavor SU(3) (F) symmetry in the respective form factors. The resulting value of the decay branching fraction, B(B (+) -> pi (+)A mu(+)A mu(-)) = (1.88 (-0.21) (+0.32) ) x 10(-8), is in good agreement with the results of measurements of the LHCb Collaboration. The branching fraction for the isospin analog of the decay under consideration is B(B (+) -> pi (+)A mu(+)A mu(-)) = (0.94 (-0.11) (+0.16) ) x 10(-8). Therefore, this decay can be measured at the Super-B factory under construction.

• 出版日期2015-5