Neutral B-meson mixing from unquenched lattice QCD with domain-wall light quarks and static b quarks

Journal Article · Thu Jul 01 04:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.82.014505· OSTI ID:21410050

Albertus, C; Flynn, J M; Sachrajda, C T ^[1]; Aoki, Y; Ishikawa, T ^[2]; Boyle, P A; Wennekers, J ^[3]; Christ, N H; Dumitrescu, T T; Loktik, O ^[4]; Izubuchi, T ^[2]; Soni, A; Van de Water, R S; Witzel, O ^[5]

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1. School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom)
2. RIKEN-BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973 (United States)
3. SUPA, School of Physics, The University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom)
4. Physics Department, Columbia University, New York, New York 10027 (United States)
5. Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)

We demonstrate a method for calculating the neutral B-meson decay constants and mixing matrix elements in unquenched lattice QCD with domain-wall light quarks and static b-quarks. Our computation is performed on the '2+1' flavor gauge configurations generated by the RBC and UKQCD Collaborations with a lattice spacing of a{approx_equal}0.11 fm (a{sup -1}=1.729 GeV) and a lattice spatial volume of approximately (1.8 fm){sup 3}. We simulate at three different light sea quark masses with pion masses down to approximately 430 MeV, and extrapolate to the physical quark masses using a phenomenologically-motivated fit function based on next-to-leading order heavy-light meson SU(2) chiral perturbation theory. For the b-quarks, we use an improved formulation of the Eichten-Hill action with static link-smearing to increase the signal-to-noise ratio. We also improve the heavy-light axial current used to compute the B-meson decay constant to O({alpha}{sub s}pa) using one-loop lattice perturbation theory. We present initial results for the SU(3)-breaking ratios f{sub B{sub s}}/f{sub B{sub d}} and {xi}=f{sub B{sub s{radical}}}(B{sub B{sub s}})/f{sub B{sub d{radical}}}(B{sub B{sub d}}), thereby demonstrating the viability of the method. For the ratio of decay constants, we find f{sub B{sub s}}/f{sub B{sub d}}=1.15(12) and for the ratio of mixing matrix elements, we find {xi}=1.13(12), where in both cases the errors reflect the combined statistical and systematic uncertainties, including an estimate of the size of neglected O(1/m{sub b}) effects.

• OSTI ID: 21410050
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 1 Vol. 82; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
B MESONS
B NEUTRAL MESONS
B QUARKS
BEAUTY MESONS
BEAUTY PARTICLES
BOSONS
CHIRALITY
COMPOSITE MODELS
COMPUTERIZED SIMULATION
D QUARKS
DECAY
DIMENSIONLESS NUMBERS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
FIELD THEORIES
FLAVOR MODEL
GEV RANGE
GEV RANGE 01-10
HADRONS
MASS
MATHEMATICAL MODELS
MATRIX ELEMENTS
MESONS
MEV RANGE
MEV RANGE 100-1000
MIXING
PARTICLE DECAY
PARTICLE MODELS
PARTICLE PROPERTIES
PERTURBATION THEORY
PIONS
PSEUDOSCALAR MESONS
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARK MODEL
QUARKS
SIGNAL-TO-NOISE RATIO
SIMULATION
U QUARKS