arXiv subjects

T. Sudmann

Publications and source records attributed to T. Sudmann.

6 recordsLinked to original sources

arXiv2009

Light Meson Physics from Maximally Twisted Mass Lattice QCD

We present a comprehensive investigation of light meson physics using maximally twisted mass fermions for two 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 MeV to 650 MeV we control the major systematic effects of our calculation. This enables us to confront our data with chiral perturbation theory and extract low energy constants of the effective chiral Lagrangian and derived quantities, such as the light quark mass, with high precision.

hep-lat↗

arXiv2008

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

In a recent paper [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.

hep-lat↗

arXiv2008

Hadron spectrum of QCD with one quark flavor

The latest results of an ongoing project for the lattice simulation of QCD with a single quark flavor are presented. The Symanzik tree-level-improved Wilson action is adopted in the gauge sector and the (unimproved) Wilson action for the fermion. Results from new simulations with one step of Stout-smearing (rho=0.15) in the fermion action are discussed. The one-flavor theory is simulated by a polynomial hybrid Monte Carlo algorithm (PHMC) at beta=4.0 corresponding to a = 0.13fm, on 16^3x32 and 24^3x48 lattices; the box-size is L = 2.1fm and L = 3.1fm, respectively. At the lightest simulated quark mass the (partially quenched) pion mass is ~300 MeV. The masses of the lightest bound states are computed, including the flavor singlet scalar and pseudoscalar mesons sigma_s and eta_s, the scalar glueball 0^++, and the Delta^++ baryon. Relics of SUSY in the mass spectrum, expected from a large N_c orientifold equivalence with the N=1 supersymmetric Yang-Mills theory, are discussed.

hep-lat↗

arXiv2007

Hadron spectrum of QCD with one quark flavor

The hadron spectrum of one flavor QCD is studied by Monte Carlo simulations. The Symanzik tree-level-improved Wilson action is used for the gauge field and the Wilson action for the fermion. The theory is simulated by a polynomial hybrid Monte Carlo algorithm (PHMC). The mass spectrum of hadronic bound states is investigated at two different lattice spacings: a ~ 0.37r_0 and a ~ 0.27r_0, corresponding to ~0.19fm and ~0.13fm in ordinary QCD. The lattice extension is fixed to L ~ 4.4r_0 (~2.2fm). The lightest simulated quark mass corresponds to a pion with mass ~270MeV. Properties of the theory are analyzed by making use of the ideas of partially quenched chiral perturbation theory (PQChPT). The symmetry of the single flavor theory can be artificially enhanced by adding extra valence quarks, which can be interpreted as u and d quarks. Operators in the valence pion sector can be built. Masses and decay constants are analyzed by using PQChPT formulae at next-to-leading order.

hep-lat↗

arXiv2007

Hadron masses in QCD with one quark flavour

One-flavour QCD - a gauge theory with SU(3) colour gauge group and a fermion in the fundamental representation - is studied by Monte Carlo simulations. The mass spectrum of hadronic bound states is investigated in a volume with extensions of L ~ 4.4r_0 (~2.2fm) at two different lattice spacings: a ~ 0.37r_0 (~0.19fm) and a ~ 0.27r_0 (~0.13fm). The lattice action is Symanzik tree-level-improved Wilson action for the gauge field and (unimproved) Wilson action for the fermion.

hep-lat↗

arXiv2006

Numerical simulation of QCD with u, d, s and c quarks in the twisted-mass Wilson formulation

A first study of numerical Monte Carlo simulations with two quark doublets, a mass-degenerate one and a mass-split one, interpreted as u, d, s and c quarks, is carried out in the framework of the twisted mass Wilson lattice formulation. Tuning the bare parameters of this theory is explored on 12^3x24 and 16^3x32 lattices at lattice spacings a=0.20fm and a=0.15fm, respectively.

hep-lat↗