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ABSTRACT: We study properties of pseudoscalar flavour-singlet mesons from Wilson
twisted mass lattice QCD with Nf=2+1+1 dynamical quark flavors. Results for
masses are presented at three values of the lattice spacing and light quark
masses corresponding to values of the pion mass from 230 MeV to 500 MeV. We
briefly discuss scaling effects and the light and strange quark mass dependence
of the eta mass. In addition we present an exploratory study using
Osterwalder-Seiler type strange and charm valence quarks. This approach avoids
some of the complications of the twisted mass heavy doublet. We present first
results for matching valence and unitary actions and a comparison of
statistical uncertainties.
11/2012;
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ABSTRACT: We investigate the continuum limit of the low lying static-light meson spectrum using Wilson twisted mass lattice QCD with
N
f
= 2 dynamical quark flavours. We consider three values of the lattice spacing a ≈ 0.051 fm, 0.064 fm, 0.080 fm and various values of the pion mass in the range 280 MeV ≲ m
PS 640 MeV. We present results in the continuum limit for light cloud angular momentum j = 1/2, 3/2, 5/2 and for parity P = +, - \mathcal{P} = +, - . We extrapolate our results to physical quark masses, make predictions regarding the spectrum of B and B
s
mesons and compare with available experimental results.
KeywordsLattice QCD–B-Physics
Journal of High Energy Physics 04/2012; 2010(8):1-20. · 5.83 Impact Factor
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ABSTRACT: We determine mass and flavour content of eta and eta' states using Nf=2+1+1
Wilson twisted mass lattice QCD. We describe how those flavour singlet states
need to be treated in this lattice formulation. Results are presented for two
values of the lattice spacing, a~0.08 fm and a~0.09 fm, with a range of light
quark masses corresponding to values of the pion mass from 270 to 500 MeV and
fixed bare strange and charm quark mass values.
11/2011;
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Remi Baron,
Philippe Boucaud,
Jaume Carbonell,
Vincent Drach,
Federico Farchioni,
Gregorio Herdoiza,
Karl Jansen, Chris Michael,
Istvan Montvay,
Elisabetta Pallante,
Olivier Pène,
Siebren Reker,
Carsten Urbach,
Marc Wagner,
Urs Wenger
Computer Physics Communications. 01/2011; 182:299-316.
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ETM Collaboration,
Remi Baron,
Philippe Boucaud,
Jaume Carbonell,
Vincent Drach,
Federico Farchioni,
Gregorio Herdoiza,
Karl Jansen, Chris Michael,
Istvan Montvay,
Elisabetta Pallante,
Siebren Reker,
Carsten Urbach,
Marc Wagner,
Urs Wenger
[show abstract]
[hide abstract]
ABSTRACT: We discuss the computation of the kaon and D meson masses in the N_f = 2+1+1 twisted mass lattice QCD setup, where explicit heavy flavor and parity breaking occurs at finite lattice spacing. We present three methods suitable in this context and verify their consistency. Comment: 7 pages, 3 figures, talk given at the XXVIII International Symposium on Lattice Field Theory (Lattice 2010), June 14-19 2010, Villasimius, Italy
09/2010;
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Remi Baron,
Philippe Boucaud,
Jaume Carbonell,
Albert Deuzeman,
Vincent Drach,
Federico Farchioni,
Vicent Gimenez,
Gregorio Herdoiza,
Karl Jansen,
Craig McNeile, Chris Michael,
Istvan Montvay,
David Palao,
Elisabetta Pallante,
Olivier Pene,
Siebren Reker,
Carsten Urbach,
Marc Wagner,
Urs Wenger,
ETM Collaboration
[show abstract]
[hide abstract]
ABSTRACT: We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (N_f = 2+1+1) dynamical quarks using Wilson twisted mass fermions at maximal twist. The tuning of the strange and charm quark masses is performed at two values of the lattice spacing a~0.078 fm and a~0.086 fm with lattice sizes ranging from L~1.9 fm to L~2.8 fm. We measure with high statistical precision the light pseudoscalar mass m_PS and decay constant f_PS in a range 270 < m_PS < 510 MeV and determine the low energy parameters f_0, l_3 and l_4 of SU(2) chiral perturbation theory. We use the two values of the lattice spacing, several lattice sizes as well as different values of the light, strange and charm quark masses to explore the systematic effects. A first study of discretisation effects in light-quark observables and a comparison to N_f=2 results are performed. Comment: 31 pages, 14 figures
Journal of High Energy Physics 04/2010; · 5.83 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: We investigate the continuum limit of the low lying static-light meson spectrum using Wilson twisted mass lattice QCD with N_f = 2 dynamical quark flavours. We consider three values of the lattice spacing a ~ 0.051 fm, 0.064 fm, 0.080 fm and various values of the pion mass in the range 280 MeV < m_PS < 640 MeV. We present results in the continuum limit for light cloud angular momentum j = 1/2, 3/2, 5/2 and for parity P = +, -. We extrapolate our results to physical quark masses, make predictions regarding the spectrum of B and B_s mesons and compare with available experimental results. Comment: 18 pages, 3 figures
04/2010;
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[show abstract]
[hide abstract]
ABSTRACT: We compute the static-light meson spectrum with N_f = 2 flavours of sea quarks using Wilson twisted mass lattice QCD. We consider five different values for the light quark mass corresponding to 300 MeV < m_PS < 600 MeV and we present results for angular momentum j = 1/2, j = 3/2 and j = 5/2 and for parity P = + and P = -. We extrapolate our results to physical quark masses and make predictions regarding the spectrum of B and B_s mesons.
11/2008;
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[show abstract]
[hide abstract]
ABSTRACT: We compute the static-light meson spectrum using two-flavor Wilson twisted mass lattice QCD. We have considered five different values for the light quark mass corresponding to 300 MeV < m_PS < 600 MeV. We have extrapolated our results, to make predictions regarding the spectrum of B and B_s mesons. Comment: 7 pages, 2 figures, talk given at the XXVI International Symposium on Lattice Field Theory, July 14 - 19 2008, Williamsburg, Virginia, USA
08/2008;
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ABSTRACT: We present results for the static-light meson from unquenched lattice QCD. The unquenched gauge configurations were generated using the non-perturbatively improved clover action. At the fixed lattice spacing of 0.1 fm the lightest sea quark mass used is a third of the strange quark mass. A comparison is made between heavy-light chiral perturbation theory and the f_B^(static) decay constant. The mass of the bottom quark is also reported: m_b(m_b) = 4.25(2)(11) GeV, where the first error is statistical and the last error is the systematic uncertainty.
10/2004;
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[show abstract]
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ABSTRACT: We compute the mass of the singlet 0++ state using both (psi_bar psi) and Wilson loop operators from a N_f=2 lattice QCD calculation.
10/2002;
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ABSTRACT: Simulations that use the clover action in quenched QCD calculations have a lower limit to the quark mass that can be reached, because of the fluctuations caused by exceptional configurations. From this low statistics study, we find that the twisted clover action, recently introduced by the ALPHA collaboration, can be used to simulate quenched QCD at quark masses below those attainable by simulations that use the clover action.
11/2001;
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ABSTRACT: We discuss in detail the extraction of hadronic mixing strengths from lattice studies. We apply this to the mixing of a scalar glueball and a scalar meson in the quenched approximation. We also measure correlations appropriate for flavour-singlet scalar mesons using dynamical quark configurations from UKQCD. This enables us to compare the results from the quenched study of the mixing with the direct determination of the mixed spectrum. Improved methods of evaluating the disconnected quark diagrams are also presented.
11/2000;
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[show abstract]
[hide abstract]
ABSTRACT: We investigate a number of algorithms that calculate the quark propagators for the overlap-Dirac fermion operator. The QCD simulations were performed at beta = 5.9 with a lattice volume of 16**3*32.
10/1999;
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[hide abstract]
ABSTRACT: We evaluate properties of neutral mesons in Nf=2 dynamical simulations of TMQCD at maximal twist. The pion is explored - establishing the size of the isospin splitting (an order a^2 effect). We investigate the eta' (the Nf=2 flavour singlet pseudoscalar meson) and neutral rho and scalar mesons. We show that disconnected diagrams can be evaluated very efficiently in TMQCD using variance reduction methods.
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[show abstract]
[hide abstract]
ABSTRACT: Simulations that use the clover action in quenched QCD calculations have a lower limit to the quark mass that can be reached, because of the fluctuations caused by exceptional configurations. From this low statistics study, we find that the twisted clover action, recently introduced by the ALPHA collaboration, can be used to simulate quenched QCD at quark masses below those attainable by simulations that use the clover action.
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[show abstract]
[hide abstract]
ABSTRACT: We compute the mass of the singlet 0++ state using bothψψ and Wilson loop operators from aNf = 2 lattice QCD calculation.
Nuclear Physics B - Proceedings Supplements.
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Remi Baron,
Philippe Boucaud,
Jaume Carbonell,
Vincent Drach,
Federico Farchioni,
Gregorio Herdoiza,
Karl Jansen, Chris Michael,
Istvan Montvay,
Elisabetta Pallante,
Olivier Pène,
Siebren Reker,
Carsten Urbach,
Marc Wagner,
Urs Wenger
[show abstract]
[hide abstract]
ABSTRACT: We discuss the computation of the mass of the K and D mesons within the framework of Nf=2+1+1 twisted mass lattice QCD from a technical point of view. These quantities are essential, already at the level of generating gauge configurations, being obvious candidates to tune the strange and charm quark masses to their physical values. In particular, we address the problems related to the twisted mass flavor and parity symmetry breaking, which arise when considering a non-degenerate (c,s) doublet. We propose and verify the consistency of three methods to extract the K and D meson masses in this framework.
Computer Physics Communications.
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[show abstract]
[hide abstract]
ABSTRACT: We investigate a number of algorithms that calculate the quark propagators for the overlap-Dirac fermion operator. The QCD simulations were performed at β = 5.9 with a lattice volume of 163 32.
Nuclear Physics B - Proceedings Supplements.
