$$B \to \pi \ell \nu$$ and $$B_s \to K \ell \nu$$ form factors and $$|V_{ub}|$$ from 2+1-flavor lattice QCD with domain-wall light quarks and relativistic heavy quarks
We calculate the form factors for B → πℓν and B s → Kℓν decay in dynamical lattice quantum chromodynamics (QCD) using domain-wall light quarks and relativistic b-quarks. We use the (2+1)-flavor gauge-field ensembles generated by the RBC and UKQCD collaborations with the domain-wall fermion action and Iwasaki gauge action. For the b-quarks we use the anisotropic clover action with a relativistic heavy-quark interpretation. 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. We simultaneously extrapolate our numerical results to the physical light-quark masses and to the continuum and interpolate in the pion/kaon energy using SU(2) “hard-pion” chiral perturbation theory for heavy-light meson form factors. We provide complete systematic error budgets for the vector and scalar form factors f + (q 2) and f 0(q 2) for both B → πℓν and B s → Kℓν at three momenta that span the q 2 range accessible in our numerical simulations. Next we extrapolate these results to q 2 = 0 using a model-independent z-parametrization based on analyticity and unitarity. We present our final results for f +(q 2) and f 0(q 2)as the coefficientsmore »
- Authors:
-
[1];
[2];
[2];
[2];
[2];
[3];
[4]
- Univ. of Southampton, Southampton (United Kingdom)
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Boston Univ., Boston, MA (United States)
- Publication Date:
- Report Number(s):
- FERMILAB-PUB-15-019-T
Journal ID: ISSN 1550-7998; arXiv eprint number arXiv:1501.05373; TRN: US1600873
- Grant/Contract Number:
- AC02-07CH11359
- Type:
- Accepted Manuscript
- Journal Name:
- Physical Review. D, Particles, Fields, Gravitation and Cosmology
- Additional Journal Information:
- Journal Volume: 91; Journal Issue: 7; Journal ID: ISSN 1550-7998
- Publisher:
- American Physical Society (APS)
- 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 Orgs:
- RBC Collaboration; UKQCD Collaboration
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
- OSTI Identifier:
- 1221234
- Alternate Identifier(s):
- OSTI ID: 1180799