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

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

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.

133002-[14pp]

Albertus, C.

2578dbb1-80bd-4f6d-a955-1e80578d79da

Flynn, J.M.

d8e90963-ba56-415c-bbd4-496b7d91d343

Hernández, E.

1eb849cb-1ace-4284-a764-a4f0efea3fa6

Nieves, J.

4d72ebe2-1ea0-4579-bd81-4c682ab01a7f

Verde-Velasco, J.M.

302e3471-c79c-4d9d-a5a1-7d98ddca5c21

2 August 2005

Albertus, C.

2578dbb1-80bd-4f6d-a955-1e80578d79da

Flynn, J.M.

d8e90963-ba56-415c-bbd4-496b7d91d343

Hernández, E.

1eb849cb-1ace-4284-a764-a4f0efea3fa6

Nieves, J.

4d72ebe2-1ea0-4579-bd81-4c682ab01a7f

Verde-Velasco, J.M.

302e3471-c79c-4d9d-a5a1-7d98ddca5c21

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), .
(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.

Full text not available from this repository.

## More information

Published date: 2 August 2005

## Identifiers

Local EPrints ID: 56956

URI: http://eprints.soton.ac.uk/id/eprint/56956

ISSN: 1550-7998

PURE UUID: ce10adf1-212f-4a87-81d7-45ce870e15db

## Catalogue record

Date deposited: 13 Aug 2008

Last modified: 26 Nov 2019 02:03

## Export record

## Altmetrics

## Contributors

Author:
C. Albertus

Author:
E. Hernández

Author:
J. Nieves

Author:
J.M. Verde-Velasco

## University divisions

## Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics