skip to main content


Title: B -meson decay constants from 2 + 1 -flavor lattice QCD with domain-wall light quarks and relativistic heavy quarks

We calculate the B-meson decay constants f B, f Bs, and their ratio in unquenched lattice QCD using domain-wall light quarks and relativistic b quarks. We use gauge-field ensembles generated by the RBC and UKQCD collaborations using the domain-wall fermion action and Iwasaki gauge action with three flavors of light dynamical quarks. We analyze data at two lattice spacings of a ≈ 0.11, 0.086 fm with unitary pion masses as light as M π ≈ 290 MeV; this enables us to control the extrapolation to the physical light-quark masses and continuum. For the b quarks we use the anisotropic clover action with the relativistic heavy-quark interpretation, such that discretization errors from the heavy-quark action are of the same size as from the light-quark sector. We renormalize the lattice heavy-light axial-vector current using a mostly nonperturbative method in which we compute the bulk of the matching factor nonperturbatively, with a small correction, that is close to unity, in lattice perturbation theory. We also improve the lattice heavy-light current through O(α sa). We extrapolate our results to the physical light-quark masses and continuum using SU(2) heavy-meson chiral perturbation theory, and provide a complete systematic error budget. We obtain f B0 = 199.5(12.6)more » MeV, f B+=195.6(14.9) MeV, f Bs=235.4(12.2) MeV, f Bs/f B0=1.197(50), and f Bs/f B+=1.223(71), where the errors are statistical and total systematic added in quadrature. Finally, these results are in good agreement with other published results and provide an important independent cross-check of other three-flavor determinations of B-meson decay constants using staggered light quarks.« less
 [1] ;  [2] ;  [3] ;  [4] ;  [3] ;  [3] ;  [5] ;  [6]
  1. Columbia Univ., New York, NY (United States)
  2. Univ. of Southampton, Southampton (United Kingdom)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
  4. RIKEN, Wako (Japan); Brookhaven National Lab. (BNL), Upton, NY (United States)
  5. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  6. Boston Univ., Boston, MA (United States)
Publication Date:
Report Number(s):
FERMILAB-PUB-14-100-T; arXiv:1404.4670
Journal ID: ISSN 1550-7998; PRVDAQ; 1291284
Grant/Contract Number:
AC02-07CH11359; FG02-92ER40699; SC0008814
Accepted Manuscript
Journal Name:
Physical Review. D, Particles, Fields, Gravitation and Cosmology
Additional Journal Information:
Journal Volume: 91; Journal Issue: 5; Journal ID: ISSN 1550-7998
American Physical Society (APS)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
RBC and UKQCD Collaborations
Country of Publication:
United States
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1181051