Status of Dynamical Fermion Simulations

215

257

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 andl 3,4 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.

“…[1,2] for recent reviews. Here, we adopt a particular type of Wilson fermions, known as the Wilson twisted mass formulation of lattice QCD (tmLQCD), introduced in [3,4].…”

Section: Introduction and Main Resultsmentioning

confidence: 99%

“…1 The positivity is monitored by measuring the smallest eigenvalue λ h,min of Q † h Q h , where Q h = γ 5 τ 3 D h and D h is the Wilson Dirac operator of the non-degenerate twisted mass action in eq. (2.5).…”

Section: Simulation Ensemblesmentioning

confidence: 99%

Light hadrons from lattice QCD with light (u, d), strange and charm dynamical quarks

Baron

Boucaud

Carbonell

et al. 2010

215

257

“…4 In closing this section we note that an independent determination of the b-quark mass can be obtained repeating the same analysis as before but using M Bs , instead of M B , and replacingμ u/d withμ s . By doing that we find a result which is fully consistent with the one in eq.…”

Section: Jhep04(2010)049mentioning

confidence: 98%

“…However, to extract from experiments useful phenomenological information, it is mandatory to have an accurate knowledge of the relevant hadronic matrix elements of the effective weak Hamiltonian. For low mass states (up to around the charm mass) lattice QCD (LQCD) represents the ideal framework where such calculations can be performed with well under control systematic errors [4][5][6]. Due to present day computer limitations, it is not possible, however, to work directly with the heaviest quarks (as the b-quark) propagating on the simulated lattice.…”

Section: Introductionmentioning

confidence: 99%

A proposal for B-physics on current lattices

Blossier

Dimopoulos²,

Frezzotti³

et al. 2010

A method to extract B-physics parameters (b-quark mass and f B , f Bs decay constants) from currently available lattice data is presented and tested. The approach is Open Access doi:10.1007/JHEP04 (2010)049 JHEP04 (2010)049 based on the idea of constructing appropriate ratios of heavy-light meson masses and decay constants, respectively, possessing a precisely known static limit, and evaluating them at various pairs of heavy quark masses around the charm. Via a smooth interpolation in the heavy quark mass from the easily accessible charm region to the asymptotic point, Bphysics parameters are computed with a few percent (statistical + systematic) error using recently produced N f = 2 maximally twisted Wilson fermions data.

“…[1,2] for recent reviews). Simulations containing the dynamics of the light-quark flavours in the sea, as well as those due to the strange quark and recently also to the charm, using pseudo scalar masses below 300 MeV, spatial lattice extents L ≥ 2 fm and lattice spacings smaller than 0.1 fm are presently being performed by several lattice groups [3][4][5][6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Light meson physics from maximally twisted mass lattice QCD

Baron

Boucaud

Dimopoulos

et al. 2010

Self Cite

128

142

We present a comprehensive investigation of light meson physics using maximally twisted mass fermions for N f = 2 mass-degenerate quark flavours. By employing four values of the lattice spacing, spatial lattice extents ranging from 2.0 fm to 2.5 fm and pseudo scalar masses in the range 280 m PS 650 MeV we control the major systematic effects of our calculation. This enables us to confront our N f = 2 data with SU(2) chiral perturbation theory and extract low energy constants of the effective chiral Lagrangian and derived quantities, such as the light quark mass.