Gregorio Herdoiza

Dynamical Twisted Mass Fermions with Light Quarks: Simulation and Analysis Details

In a recent paper [ETMC, P. Boucaud et al., Phys. Lett. B 650 (2007) 304, hep-lat/0701012] we presented precise lattice QCD results of our European Twisted Mass Collaboration (ETMC). They were obtained by employing two mass-degenerate flavours of twisted mass fermions at maximal twist. In the present paper we give details on our simulations and the computation of physical observables. In particular, we discuss the problem of tuning to maximal twist, the techniques we have used to compute correlators and error estimates. In addition, we provide more information on the algorithm used, the autocorrelation times and scale determination, the evaluation of disconnected contributions and the description of our data by means of chiral perturbation theory formulae.

Light Meson Physics from Maximally Twisted Mass Lattice QCD

We present a comprehensive investigation of light meson physics using maximally twisted mass fermions for Nf = 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 ≲ mPS ≲ 650MeV we control the major systematic effects of our calculation. This enables us to confront our Nf = 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.

Computing K and D meson masses with N_f = 2+1+1 twisted mass lattice QCD

We discuss the computation of the mass of the K and D mesons within the framework of N-f = 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. (c) 2010 Elsevier By. All rights reserved.

Simulation of QCD with N f = 2 + 1 flavors of non-perturbatively improved Wilson fermions

A bstractWe describe a new set of gauge configurations generated within the CLS effort. These ensembles have Nf = 2 + 1 flavors of non-perturbatively improved Wilson fermions in the sea with the Lüscher-Weisz action used for the gluons. Open boundary conditions in time are used to address the problem of topological freezing at small lattice spacings and twisted-mass reweighting for improved stability of the simulations. We give the bare parameters at which the ensembles have been generated and how these parameters have been chosen. Details of the algorithmic setup and its performance are presented as well as measurements of the pion and kaon masses alongside the scale parameter t0.

Lattice QCD determination of m b , f B and f Bs with twisted mass Wilson fermions

A bstractWe present a lattice QCD determination of the b quark mass and of the B and Bs decay constants, performed with Nf = 2 twisted mass Wilson fermions, by simulating at four values of the lattice spacing. In order to study the b quark on the lattice, two methods are adopted in the present work, respectively based on suitable ratios with exactly known static limit and on the interpolation between relativistic data, evaluated in the charm mass region, and the static point, obtained by simulating the HQET on the lattice. The two methods provide results in good agreement. For the b quark mass in the

Computing K and D meson masses with N-f=2+1+1 twisted mass lattice QCD

\overline {\text{MS}}

First lattice QCD estimate of the g(D* D pi) coupling

scheme and for the decay constants we obtain

The hadronic vacuum polarization contribution to the muon g − 2 from lattice QCD

{\overline m_b}\left( {{{\overline m }_b}} \right)

Sigma terms and strangeness content of the nucleon with N f = 2 + 1 + 1 twisted mass fermions

= 4.29(14) GeV, fB = 195(12) MeV, fBs = 232(10) MeV and fBs/fB = 1.19(5). As a byproduct of the analysis we also obtain the results for the fD and fDs decay constants: fD = 212(8) MeV, fDs = 248(6) MeV and fDs/fD = 1.17(5).

Pseudoscalar Decay Constants from

We discuss the computation of the mass of the K and D mesons within the framework of N-f = 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. (c) 2010 Elsevier By. All rights reserved.