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Title: B*Bπ coupling using relativistic heavy quarks

We report on a calculation of the B*Bπ coupling in lattice QCD. The strong matrix element (Bπ|B*) is directly related to the leading order low-energy constant in heavy meson chiral perturbation theory (HM ΧPT) for B mesons. We carry out our calculation directly at the b-quark mass using a non-perturbatively tuned clover action that controls discretization effects of order |p a| and (ma) n for all n. Our analysis is performed on RBC/UKQCD gauge configurations using domain-wall fermions and the Iwasaki gauge action at two lattice spacings of a –1 = 1.729(25) GeV, a –1 = 2.281 (28) GeV, and unitary pion masses down to 290 MeV. We achieve good statistical precision and control all systematic uncertainties, giving a final result for the HM ΧPT coupling g b = 0.56(3) stat(7) sys in the continuum and at the physical light-quark masses. Furthermore, this is the first calculation performed directly at the physical b-quark mass and lies in the region one would expect from carrying out an interpolation between previous results at the charm mass and at the static point.
 [1] ;  [2] ;  [3] ;  [3] ;  [1] ;  [1] ;  [4] ;  [5]
  1. Univ. of Southampton, Southampton (United Kingdom)
  2. Humboldt Univ., Berlin (Germany)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
  4. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  5. Boston Univ., Boston, MA (United States)
Publication Date:
Report Number(s):
FERMILAB-PUB-15-256-T; BNL-112233-2016-JA
Journal ID: ISSN 2470-0010; PRVDAQ; arXiv eprint number arXiv:1506.06413
Grant/Contract Number:
AC02-07CH11359; SC00112704
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 93; Journal Issue: 1; Journal ID: ISSN 2470-0010
American Physical Society (APS)
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Brookhaven National Laboratory (BNL), Upton, NY (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
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; QCD; coupling; quarks; lattice; flavour
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1236284; OSTI ID: 1254819