$$B\to\pi\ell\nu$$ semileptonic form factors from unquenched lattice QCD and determination of $$|V_{ub}|$$
Abstract
We compute the $$B\to\pi\ell\nu$$ semileptonic form factors and update the determination of the CKM matrix element $$|V_{ub}|$$. We use the MILC asqtad ensembles with $$N_f=2+1$$ sea quarks at four different lattice spacings in the range $$a \approx 0.045$$~fm to $0.12$~fm. The lattice form factors are extrapolated to the continuum limit using SU(2) staggered chiral perturbation theory in the hard pion limit, followed by an extrapolation in $q^2$ to the full kinematic range using a functional $$z$$-parameterization. The extrapolation is combined with the experimental measurements of the partial branching fraction to extract $$|V_{ub}|$$. Our preliminary result is $$|V_{ub}|=(3.72\pm 0.14)\times 10^{-3}$$, where the error reflects both the lattice and experimental uncertainties, which are now on par with each other.
- Authors:
- Publication Date:
- Research Org.:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- Contributing Org.:
- Fermilab Lattice; MILC
- OSTI Identifier:
- 1327265
- Report Number(s):
- arXiv:1411.6038; FERMILAB-CONF-14-518-T
1329797
- DOE Contract Number:
- AC02-07CH11359
- Resource Type:
- Conference
- Journal Name:
- PoS
- Additional Journal Information:
- Journal Volume: LATTICE2014; Conference: 32nd International Symposium on Lattice Field Theory, Brookhaven, NY, USA, 06/23-06/28/2014
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
Citation Formats
Du, Daping, and et al. $B\to\pi\ell\nu$ semileptonic form factors from unquenched lattice QCD and determination of $|V_{ub}|$. United States: N. p., 2014.
Web.
Du, Daping, & et al. $B\to\pi\ell\nu$ semileptonic form factors from unquenched lattice QCD and determination of $|V_{ub}|$. United States.
Du, Daping, and et al. 2014.
"$B\to\pi\ell\nu$ semileptonic form factors from unquenched lattice QCD and determination of $|V_{ub}|$". United States. https://www.osti.gov/servlets/purl/1327265.
@article{osti_1327265,
title = {$B\to\pi\ell\nu$ semileptonic form factors from unquenched lattice QCD and determination of $|V_{ub}|$},
author = {Du, Daping and et al.},
abstractNote = {We compute the $B\to\pi\ell\nu$ semileptonic form factors and update the determination of the CKM matrix element $|V_{ub}|$. We use the MILC asqtad ensembles with $N_f=2+1$ sea quarks at four different lattice spacings in the range $a \approx 0.045$~fm to $0.12$~fm. The lattice form factors are extrapolated to the continuum limit using SU(2) staggered chiral perturbation theory in the hard pion limit, followed by an extrapolation in $q^2$ to the full kinematic range using a functional $z$-parameterization. The extrapolation is combined with the experimental measurements of the partial branching fraction to extract $|V_{ub}|$. Our preliminary result is $|V_{ub}|=(3.72\pm 0.14)\times 10^{-3}$, where the error reflects both the lattice and experimental uncertainties, which are now on par with each other.},
doi = {},
url = {https://www.osti.gov/biblio/1327265},
journal = {PoS},
number = ,
volume = LATTICE2014,
place = {United States},
year = {Sun Nov 23 00:00:00 EST 2014},
month = {Sun Nov 23 00:00:00 EST 2014}
}