Semileptonic B -> pi decays from an Omnès improved nonrelativistic constituent quark model

Albertus, C., Flynn, J.M., Hernández, E., Nieves, J. and Verde-Velasco, J.M. (2005) Semileptonic B -> pi decays from an Omnès improved nonrelativistic constituent quark model. Physical Review D, 72 (3), 133002-[14pp]. (doi:10.1103/PhysRevD.72.033002).

Abstract

The semileptonic B{yields}{pi}l{sup +}{nu}{sub l} decay is studied starting from a simple quark model which includes the influence of the B* pole. To extend the predictions of a nonrelativistic constituent quark model from its region of applicability near q{sub max}{sup 2}=(m{sub B}-m{sub {pi}}){sup 2} to all q{sup 2} values accessible in the physical decay, we use a novel multiply subtracted Omnes dispersion relation, which considerably diminishes the form-factor dependence on the elastic {pi}B{yields}{pi}B scattering amplitudes at high energies. By comparison to the experimental branching fraction we extract |V{sub ub}|=0.0034{+-}0.0003(exp){+-}0.0007(theory). To further test our framework, we also study D{yields}{pi} and D{yields}K decays and find excellent results f{sub {pi}}{sup +}(0)/f{sub K}{sup +}(0)=0.80{+-}0.03, B(D{sup 0}{yields}{pi}{sup -}e{sup +}{nu}{sub e})/B(D{sup 0}{yields}K{sup -}e{sup +}{nu}{sub e})=0.079{+-}0.008. In particular for the D{yields}{pi} case, we reproduce, with high accuracy, the three-flavor lattice QCD results recently obtained by the Fermilab-MILC-HPQCD Collaboration. While for the D{yields}K case, we successfully describe the data for f{sup +}(q{sup 2})/f{sup +}(0) recently measured by the FOCUS Collaboration.

This record has no associated files available for download.

Contributors

Author: J.M. Flynn

Download statistics