Publications (7)14.74 Total impact
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Article: Precise charm to strange mass ratio and light quark masses from full lattice QCD.
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ABSTRACT: By using a single formalism to handle charm, strange, and light valence quarks in full lattice QCD for the first time, we are able to determine ratios of quark masses to 1%. For m(c)/m(s) we obtain 11.85(16), an order of magnitude more precise than the current PDG average. Combined with 1% determinations of the charm quark mass now possible this gives m(s)(2 GeV)=92.4(1.5) MeV. The MILC result for m(s)/m(l)=27.2(3) yields m(l)(2 GeV)=3.40(7) MeV for the average of u and d quark masses.Physical Review Letters 04/2010; 104(13):132003. · 7.37 Impact Factor -
Article: Prediction of the B{c}{*} mass in full lattice QCD.
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ABSTRACT: By using the highly improved staggered quark formalism to handle charm, strange, and light valence quarks in full lattice QCD, and NRQCD to handle bottom valence quarks, we are able to determine accurately ratios of the B meson vector-pseudoscalar mass splittings, in particular, [m(B{c}{*})-m(B{c})]/[m(B{s}{*})-m(B{s})]. We find this ratio to be 1.15(15), showing the "light" quark mass dependence of this splitting to be very small. Hence we predict m(B{c}{*})=6.330(7)(2)(6) GeV, where the first two errors are from the lattice calculation and the third from existing experiment. This is the most accurate prediction of a gold-plated hadron mass from lattice QCD to date.Physical Review Letters 01/2010; 104(2):022001. · 7.37 Impact Factor -
Article: Moving NRQCD for heavy-to-light form factors on the lattice
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ABSTRACT: We formulate Non-Relativistic Quantum Chromodynamics (NRQCD) on a lattice which is boosted relative to the usual discretization frame. Moving NRQCD (mNRQCD) allows us to treat the momentum for the heavy quark arising from the frame choice exactly. We derive mNRQCD through O(1/m^2,v^4), as accurate as the NRQCD action in present use, both in the continuum and on the lattice with O(a^4) improvements. We have carried out extensive tests of the formalism through calculations of two-point correlators for both heavy-heavy (bottomonium) and heavy-light (B_s) mesons in 2+1 flavor lattice QCD and obtained nonperturbative determinations of energy shift and external momentum renormalization. Comparison to perturbation theory at O(\alpha_s) is also made. The results demonstrate the effectiveness of mNRQCD. In particular we show that the decay constants of heavy-light and heavy-heavy mesons can be calculated with small systematic errors up to much larger momenta than with standard NRQCD. Comment: 34 pages. v2: accepted version, updated tables and figures, conclusions unchanged06/2009; -
Article: Precision $B_c$ and $B_s$ mass calculations
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ABSTRACT: We give improved results for B meson masses using NRQCD $b$ quarks and HISQ light valence quarks for a range of lattice spacings and sea quark masses enabling controlled extrapolation to the physical point. Comment: 6 pages, 3 figures, poster presented at the XXVI International Symposium on Lattice Field Theory, July 14-19, 2008, Williamsburg, Virginia, USA10/2008; -
Article: Matching the Bare and MSbar Charm Quark Masses Using Weak Coupling Simulations
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ABSTRACT: We provide a new determination of the charm quark mass using the Highly Improved Staggered Quark (HISQ) action, finding m_c(3 GeV) = 0.983(23) GeV. Our determination makes extensive use of second order lattice perturbation theory in matching the bare lattice mass to the MSbar scheme. This matching utilises both traditional diagrammatic perturbation theory and weak coupling simulations. The second of these techniques allows us to extract perturbative coefficients from Monte-Carlo simulations and the process of doing this is laid out in some detail here. Comment: 7 pages, 4 figures, talk presented at the XXVI International Symposium on Lattice Field Theory, July 14-19, 2008, Williamsburg, Virginia, USA10/2008; -
Article: B Semileptonic Decays at High Recoil Momentum
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ABSTRACT: We explore the possibility of studying $B\to\pi l\nu$ semileptonic decays at large recoil momentum. Our methods include the use of a random-wall source for the pion to reduce statistical errors, and different smearing functions are used for the B meson to improve the overlap with the ground state. We observe, in general, a factor of 3-4 improvement in the signal-to-noise ratio in correlation functions if random-wall propagators are used.11/2007; -
Article: Moving nonrelativistic QCD for heavy-to-light form factors on the lattice
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ABSTRACT: Journal articlePhys. Rev. D 80(2009),074505.
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Institutions
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2010
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University of Glasgow
- School of Physics and Astronomy
Glasgow, SCT, United Kingdom
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