# B- and D-meson decay constants from three-flavor lattice QCD

## Abstract

We calculate the leptonic decay constants of B_{(s)} and D_{(s)} mesons in lattice QCD using staggered light quarks and Fermilab bottom and charm quarks. We compute the heavy-light meson correlation functions on the MILC asqtad-improved staggered gauge configurations which include the effects of three light dynamical sea quarks. We simulate with several values of the light valence- and sea-quark masses (down to ~m_s/10) and at three lattice spacings (a ~ 0.15, 0.12, and 0.09 fm) and extrapolate to the physical up and down quark masses and the continuum using expressions derived in heavy-light meson staggered chiral perturbation theory. We renormalize the heavy-light axial current using a mostly nonperturbative method such that only a small correction to unity must be computed in lattice perturbation theory and higher-order terms are expected to be small. We obtain f_{B^+} = 196.9(8.9) MeV, f_{B_s} = 242.0(9.5) MeV, f_{D^+} = 218.9(11.3) MeV, f_{D_s} = 260.1(10.8) MeV, and the SU(3) flavor-breaking ratios f_{B_s}/f_{B} = 1.229(26) and f_{D_s}/f_{D} = 1.188(25), where the numbers in parentheses are the total statistical and systematic uncertainties added in quadrature.

- Authors:

- Brookhaven National Laboratory (BNL), Upton, NY (United States)

- Publication Date:

- Research Org.:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)

- Contributing Org.:
- Fermilab Lattice and MILC Collaborations

- OSTI Identifier:
- 1155767

- Report Number(s):
- FERMILAB-PUB-11-651-T

Journal ID: ISSN 1550-7998; arXiv eprint number arXiv:1112.3051

- DOE Contract Number:
- AC02-07CH11359

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physical Review. D, Particles, Fields, Gravitation and Cosmology; Journal Volume: 85; Journal Issue: 11

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

### Citation Formats

```
Bazavov, A., and et al..
```*B- and D-meson decay constants from three-flavor lattice QCD*. United States: N. p., 2012.
Web. doi:10.1103/PhysRevD.85.114506.

```
Bazavov, A., & et al..
```*B- and D-meson decay constants from three-flavor lattice QCD*. United States. doi:10.1103/PhysRevD.85.114506.

```
Bazavov, A., and et al.. Fri .
"B- and D-meson decay constants from three-flavor lattice QCD". United States. doi:10.1103/PhysRevD.85.114506. https://www.osti.gov/servlets/purl/1155767.
```

```
@article{osti_1155767,
```

title = {B- and D-meson decay constants from three-flavor lattice QCD},

author = {Bazavov, A. and et al.},

abstractNote = {We calculate the leptonic decay constants of B_{(s)} and D_{(s)} mesons in lattice QCD using staggered light quarks and Fermilab bottom and charm quarks. We compute the heavy-light meson correlation functions on the MILC asqtad-improved staggered gauge configurations which include the effects of three light dynamical sea quarks. We simulate with several values of the light valence- and sea-quark masses (down to ~m_s/10) and at three lattice spacings (a ~ 0.15, 0.12, and 0.09 fm) and extrapolate to the physical up and down quark masses and the continuum using expressions derived in heavy-light meson staggered chiral perturbation theory. We renormalize the heavy-light axial current using a mostly nonperturbative method such that only a small correction to unity must be computed in lattice perturbation theory and higher-order terms are expected to be small. We obtain f_{B^+} = 196.9(8.9) MeV, f_{B_s} = 242.0(9.5) MeV, f_{D^+} = 218.9(11.3) MeV, f_{D_s} = 260.1(10.8) MeV, and the SU(3) flavor-breaking ratios f_{B_s}/f_{B} = 1.229(26) and f_{D_s}/f_{D} = 1.188(25), where the numbers in parentheses are the total statistical and systematic uncertainties added in quadrature.},

doi = {10.1103/PhysRevD.85.114506},

journal = {Physical Review. D, Particles, Fields, Gravitation and Cosmology},

number = 11,

volume = 85,

place = {United States},

year = {Fri Jun 01 00:00:00 EDT 2012},

month = {Fri Jun 01 00:00:00 EDT 2012}

}