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Title: B -> d* l nu and b -> d l nu form-factors in staggered chiral perturbation theory

Abstract

We calculate the B {yields} D and B {yields} D* form factors at zero recoil in Staggered Chiral Perturbation Theory. We consider heavy-light mesons in which only the light (u, d, or s) quark is staggered; current lattice simulations generally use a highly improved action such as the Fermilab or NRQCD action for the heavy (b or c) quark. We work to lowest order in the heavy quark expansion and to next-to-leading order in the chiral expansion. We present results for a partially quenched theory with three sea quarks in which there are no mass degeneracies (the ''1+1+1'' theory) and for a partially quenched theory in which the u and d sea quark masses are equal (the ''2+1'' theory). We also present results for full (2+1) QCD, along with a numerical estimate of the size of staggered discretization errors. Finally, we calculate the finite volume corrections to the form factors and estimate their numerical size in current lattice simulations.

Authors:
; ;
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
879125
Report Number(s):
FERMILAB-PUB-05-534-T
arXiv eprint number hep-lat/0512007; TRN: US0700926
DOE Contract Number:
AC02-76CH03000
Resource Type:
Journal Article
Resource Relation:
Journal Name: Phys.Rev.D73:054501,2006
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; FERMILAB; FORM FACTORS; MESONS; PERTURBATION THEORY; QUANTUM CHROMODYNAMICS; QUARKS; SEAS; Lattice, Phenomenology-HEP

Citation Formats

Laiho, Jack, Van de Water, Ruth S., and /Fermilab. B -> d* l nu and b -> d l nu form-factors in staggered chiral perturbation theory. United States: N. p., 2005. Web.
Laiho, Jack, Van de Water, Ruth S., & /Fermilab. B -> d* l nu and b -> d l nu form-factors in staggered chiral perturbation theory. United States.
Laiho, Jack, Van de Water, Ruth S., and /Fermilab. Thu . "B -> d* l nu and b -> d l nu form-factors in staggered chiral perturbation theory". United States. doi:. https://www.osti.gov/servlets/purl/879125.
@article{osti_879125,
title = {B -> d* l nu and b -> d l nu form-factors in staggered chiral perturbation theory},
author = {Laiho, Jack and Van de Water, Ruth S. and /Fermilab},
abstractNote = {We calculate the B {yields} D and B {yields} D* form factors at zero recoil in Staggered Chiral Perturbation Theory. We consider heavy-light mesons in which only the light (u, d, or s) quark is staggered; current lattice simulations generally use a highly improved action such as the Fermilab or NRQCD action for the heavy (b or c) quark. We work to lowest order in the heavy quark expansion and to next-to-leading order in the chiral expansion. We present results for a partially quenched theory with three sea quarks in which there are no mass degeneracies (the ''1+1+1'' theory) and for a partially quenched theory in which the u and d sea quark masses are equal (the ''2+1'' theory). We also present results for full (2+1) QCD, along with a numerical estimate of the size of staggered discretization errors. Finally, we calculate the finite volume corrections to the form factors and estimate their numerical size in current lattice simulations.},
doi = {},
journal = {Phys.Rev.D73:054501,2006},
number = ,
volume = ,
place = {United States},
year = {Thu Dec 01 00:00:00 EST 2005},
month = {Thu Dec 01 00:00:00 EST 2005}
}
  • We calculate the B{yields}D and B{yields}D* form factors at zero recoil in staggered chiral perturbation theory. We consider heavy-light mesons in which only the light (u, d, or s) quark is staggered; current lattice simulations generally use a highly improved action such as the Fermilab or nonrelativistic QCD action for the heavy (b or c) quark. We work to lowest nontrivial order in the heavy-quark expansion and to one-loop order in the chiral expansion. We present results for a partially quenched theory with three sea quarks in which there are no mass degeneracies (the ''1+1+1'' theory) and for a partiallymore » quenched theory in which the u and d sea quark masses are equal (the ''2+1'' theory). We also present results for full (2+1) QCD, along with a numerical estimate of the size of staggered discretization errors. Finally, we calculate the finite volume corrections to the form factors and estimate their numerical size in current lattice simulations.« less
  • The exclusive semileptonic decays B{r_arrow}D{sub 1}(2420)l{bar {nu}} and B{r_arrow}D{sub 2}{sup *}(2460)l{bar {nu}} are studied at the subleading order of heavy quark expansion. The subleading Isgur-Wise functions resulting from the kinetic energy and chromomagnetic corrections to the HQET Lagrangian are calculated by QCD sum rules in the framework of heavy quark effective theory. The decay rates and branching ratios are computed with the inclusion of the order of 1/m{sub Q} corrections. It is found that the 1/m{sub Q} correction to the decay rate is not large for B{r_arrow}D{sub 2}{sup *} but is very large for B{r_arrow}D{sub 1}.
  • We present a measurement of the lepton decay asymmetry [ital A][sub fb] in the reaction [ital [bar B]][r arrow][ital D][sup *][ital l[minus]][bar [nu]][sub [ital l]] using data collected with the CLEO II detector at the Cornell Electron Storage Ring (CESR). The value of [ital A][sub fb] confirms that the chirality of the weak interaction is predominantly left-handed in [ital b][r arrow][ital c] transitions as expected in the standard model, if it is assumed that the lepton current is also left-handed. Using [ital A][sub fb] and the previously determined branching ratio, [ital q][sup 2] distribution, and [ital D][sup *] polarization, wemore » obtain the first measurement of the form-factor ratios that are used to describe this semileptonic decay.« less
  • We present a combined measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub cb}| and of the parameters {rho}{sup 2}, R{sub 1}(1), and R{sub 2}(1), which fully characterize the form factors for the B{sup 0}{yields}D*{sup -}l{sup +}{nu}{sub l} decay in the framework of heavy-quark effective field theory. The results, based on a selected sample of about 52 800 B{sup 0}{yields}D*{sup -}l{sup +}{nu}{sub l} decays, recorded by the BABAR detector, are {rho}{sup 2}=1.157{+-}0.094{+-}0.027, R{sub 1}(1)=1.327{+-}0.131{+-}0.043, R{sub 2}(1)=0.859{+-}0.077{+-}0.021, and F(1)|V{sub cb}|=(34.7{+-}0.4{+-}1.0)x10{sup -3}. The first error is the statistical and the second is the systematic uncertainty. Combining these measurements with the previous BABAR measurement ofmore » the form factors, which employs a different fit technique on a partial sample of the data, we improve the statistical precision of the result, {rho}{sup 2}=1.191{+-}0.048{+-}0.028, R{sub 1}(1)=1.429{+-}0.061{+-}0.044, R{sub 2}(1)=0.827{+-}0.038{+-}0.022, and F(1)|V{sub cb}|=(34.4{+-}0.3{+-}1.1)x10{sup -3}. Using lattice calculations for the axial form factor F(1), we extract |V{sub cb}|=(37.4{+-}0.3{+-}1.2{+-}{sub 1.4}{sup 1.2})x10{sup -3}, where the third error is due to the uncertainty in F(1). We also present a measurement of the exclusive branching fraction, B=(4.69{+-}0.04{+-}0.34)%.« less
  • We discuss the possible corrections of some recent calculations on the form factors which parametrize the matrix element of the decays {ital B}({ital D}){r_arrow}{pi}{ital l}{nu}. These calculations are based on the assumption that the {ital B}{sup {asterisk}}({ital D}{sup {asterisk}}) pole contribution is fully dominant near zero recoil. By using the Bethe-Salpeter approach, we calculate some low-lying state pole terms predicted by the quark model. The numerical results are obtained to the next-leading order of the 1/{ital M} expansion. {copyright} {ital 1996 The American Physical Society.}