English
Related papers

Related papers: Light quarks with twisted mass fermions

200 papers

We present the recent Fermilab calculations of the masses of the light quarks, using tadpole-improved Sheikholeslami-Wohlert (SW) quarks. Various sources of systematic errors are studied. Our final result for the average light quark mass in…

High Energy Physics - Lattice · Physics 2010-11-19 T. Onogi , A. X. El-Khadra , B. J. Gough , G. M. Hockney , A. S. Kronfeld , P. B. Mackenzie , B. P. Mertens , J. N. Simone

We perform the first full decomposition of the pion momentum into its gluon and quark contributions. We employ an ensemble generated by the Extended Twisted Mass Collaboration with $N_f=2 + 1 +1$ Wilson twisted mass clover fermions at…

We report on our first set of results for charm physics, using a mixed-action setup with maximally twisted valence fermions on CLS $N_f=2+1$ ensembles. This setup avoids the need of improvement coefficients to subtract $O(am_c)$ effects.…

High Energy Physics - Lattice · Physics 2022-12-22 Alessandro Conigli , Julien Frison , Gregorio Herdoíza , Carlos Pena , Alejandro Sáez , Javier Ugarrio

In this proceeding contribution we report on the ongoing effort to understand and simulate Wilson twisted mass fermions in the so called epsilon regime.

High Energy Physics - Lattice · Physics 2010-01-21 K. Jansen , A. Nube , A. Shindler

We determine the phase diagram and pion spectrum for Wilson and twisted-mass fermions in the presence of non-degeneracy between the up and down quark and discretization errors, using Wilson and twisted-mass chiral perturbation theory. We…

High Energy Physics - Lattice · Physics 2014-12-03 Derek P. Horkel , Stephen R. Sharpe

We show that the application of twisted mass QCD (tmQCD) with four (Wilson) quark flavours to the computation of lattice weak matrix elements relevant to $\Delta I=1/2$ transitions has important advantages: the renormalisation of $K \to…

High Energy Physics - Lattice · Physics 2009-11-07 C. Pena , S. Sint , A. Vladikas

We study effective energies of heavy-light meson correlation functions in lattice QCD and a small volume of (0.2 fm)^4 to non-perturbatively calculate their dependence on the heavy quark mass in the continuum limit. Our quenched results…

High Energy Physics - Lattice · Physics 2009-11-10 Jochen Heitger , Jan Wennekers

Low energy precision experiments provide significant tests of the laws of nature that can reveal physics beyond the Standard Model. A good theoretical understanding of the low energy properties of QCD is required for this purpose. The…

High Energy Physics - Phenomenology · Physics 2014-11-20 H. Leutwyler

The problem of unphysical zero modes in lattice QCD with Wilson fermions can be solved in a clean way by including a mass term proportional to $i \psibar \gamma_5 \tau^3 \psi$ in the standard lattice theory with Nf=2 mass degenerate Wilson…

High Energy Physics - Lattice · Physics 2015-06-25 Roberto Frezzotti , Pietro Antonio Grassi , Stefan Sint , Peter Weisz

We present an update of our study of the phase diagram of two-flavour QCD at zero baryon density with dynamical $O(a)$ improved Wilson quarks. All simulations are done on lattices with a temporal extent of $N_t=16$ and spatial extent…

High Energy Physics - Lattice · Physics 2013-11-01 Bastian B. Brandt , Anthony Francis , Harvey B. Meyer , Owe Philipsen , Hartmut Wittig

We apply an Osterwalder-Seiler version of twisted mass QCD to a study of the $B_K$ parameter, in which three of the four quark fields making up the relevant $\Delta S =2$ operator are maximally twisted with the same twist angle, while the…

High Energy Physics - Lattice · Physics 2010-04-15 P. Dimopoulos , H. Simma , A. Vladikas

Quark mass reweighting can be used to tune the mass of dynamical quarks. The basic idea is to use gauge field ensembles generated at some bare mass parameters to evaluate observables at different bare sea quark masses. This involves the…

High Energy Physics - Lattice · Physics 2015-01-28 Björn Leder , Jacob Finkenrath

We compute the strange and the average up/down quark masses in the quenched approximation of lattice QCD, by using the O(a)-improved Wilson action and operators and by implementing the non-perturbative renormalization. Our computation is…

High Energy Physics - Lattice · Physics 2008-11-26 Damir Becirevic , Vittorio Lubicz , Cecilia Tarantino

Quantum Chromodynamics on a lattice with Wilson fermions and a chirally twisted mass term for two degenerate quark flavours is considered in the framework of chiral perturbation theory. The pion masses and decay constants are calculated in…

High Energy Physics - Lattice · Physics 2010-12-23 Gernot Münster , Christian Schmidt , Enno E. Scholz

We present preliminary results achieved within a recently started project dealing with QCD thermodynamics in the presence of a fully dynamical second quark family. We are employing the Wilson twisted mass discretization. To reduce the…

High Energy Physics - Lattice · Physics 2014-03-28 Florian Burger , Grit Hotzel , Michael Müller-Preussker , Ernst-Michael Ilgenfritz , Maria Paola Lombardo

We present results for the b \bar b spectrum obtained using an O(M_bv^6)-correct non-relativistic lattice QCD action, where M_b denotes the bare b-quark mass and v^2 is the mean squared quark velocity. Propagators are evaluated on SESAM's…

High Energy Physics - Lattice · Physics 2009-10-30 N. Eicker , J. Fingberg , S. Güsken , H. Hoeber , Th. Lippert , K. Schilling , A. Spitz , J. Viehoff

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.…

High Energy Physics - Lattice · Physics 2008-11-26 T. Chiarappa , F. Farchioni , K. Jansen , I. Montvay , E. E. Scholz , L. Scorzato , T. Sudmann , C. Urbach

Twisted mass lattice QCD (tmQCD), generalised to four Wilson quark flavours, can be used for the computation of some weak matrix elements related to $\Delta I=1/2$ transitions. Besides eliminating unphysical zero modes, tmQCD may alleviate…

High Energy Physics - Lattice · Physics 2008-11-26 C. Pena , S. Sint , A. Vladikas

Recent conceptual, algorithmic and technical advances allow numerical simulations of lattice QCD with Wilson quarks to be performed at significantly smaller quark masses than was possible before. Here we report on simulations of two-flavour…

High Energy Physics - Lattice · Physics 2010-02-03 L. Del Debbio , L. Giusti , M. Lüscher , R. Petronzio , N. Tantalo

We develop quenched chiral perturbation theory for vector mesons made of light quarks, in the limit where the vector meson masses are much larger than the pion mass. We use this theory to extract the leading nonanalytic dependence of the…

High Energy Physics - Phenomenology · Physics 2009-10-30 Michael Booth , George Chiladze , Adam F. Falk