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Related papers: Four quark operators in maximally twisted Wilson L…

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We propose to stabilise HMC simulations of lattice QCD with very light Wilson quarks by splitting the quark determinant into two factors and by treating the factor that includes the contribution of the low modes of the Dirac operator as a…

High Energy Physics - Lattice · Physics 2010-01-21 Martin Lüscher , Filippo Palombi

A transformation is devised to convert any lattice Dirac fermion operator into a Ginsparg-Wilson Dirac fermion operator. For the standard Wilson-Dirac lattice fermion operator, the transformed new operator is local, free of O(a) lattice…

High Energy Physics - Lattice · Physics 2011-02-16 Ting-Wai Chiu

We present a lattice QCD determination of the b quark mass and of the B and B_s decay constants, performed with N_f=2 twisted mass Wilson fermions, by simulating at four values of the lattice spacing. In order to study the b quark on the…

Using Wilson fermions, we study SU(2) lattice QCD with the chemical potential at $\beta=1.6$. The ratio of fermion determinants is evaluated at each Metropolis link update step. We calculate the baryon number density, the Polyakov loops and…

High Energy Physics - Lattice · Physics 2009-10-31 S. Muroya , A. Nakamura , C. Nonaka

The first phase of a heavy quark program based on twisted mass valence quarks has been presented at last years's lattice conference. The CLS $N_f=2+1$ ensembles were used for their fine lattice spacing, while twisting the masses is expected…

High Energy Physics - Lattice · Physics 2019-11-07 Julien Frison , Andrea Bussone , Gregorio Herdoíza , Carlos Pena , Jose Ángel Romero , Javier Ugarrio

We present a reduction method for Wilson Dirac fermions with non-zero chemical potential which generates a dimensionally reduced fermion matrix. The size of the reduced fermion matrix is independent of the temporal lattice extent and the…

High Energy Physics - Lattice · Physics 2011-02-18 Andrei Alexandru , Urs Wenger

We show how the hopping parameter expansion at order $\kappa^2$ and $\kappa^4$ can be exploited in the simulation of lattice QCD with two flavours of degenerate Wilson fermions. A natural extension of this idea is a "UV-filtering" by using…

High Energy Physics - Lattice · Physics 2018-07-04 Martin Hasenbusch

We present a high order perturbative computation of the renormalization constants Z_V, Z_A and of the ratio Z_P/Z_S for Wilson fermions. The computational setup is the one provided by the RI'-MOM scheme. Three- and four-loop expansions are…

High Energy Physics - Lattice · Physics 2008-11-26 F. Di Renzo , V. Miccio , L. Scorzato , C. Torrero

We present the results of the recent high precision lattice calculation of the average up/down, strange and charm quark masses performed by ETMC with Nf=2 twisted mass Wilson fermions. The analysis includes data at four values of the…

High Energy Physics - Lattice · Physics 2011-04-22 B. Blossier , P. Dimopoulos , R. Frezzotti , V. Lubicz , M. Petschlies , G. C. Rossi , F. Sanfilippo , S. Simula , C. Tarantino

Perturbative and non-perturbative results are presented on the renormalization constants of the quark field and the vector, axial-vector, pseudoscalar, scalar and tensor currents. The perturbative computation, carried out at one-loop level…

High Energy Physics - Lattice · Physics 2013-05-30 C. Alexandrou , M. Constantinou , T. Korzec , H. Panagopoulos , F. Stylianou

We calculate the kaon $B$-parameter in quenched lattice QCD at $\beta=6.0$ using Wilson fermions at $\kappa=0.154$ and $0.155$. We use two kinds of non-local (``smeared'') sources for quark propagators to calculate the matrix elements…

High Energy Physics - Lattice · Physics 2009-10-22 Gupta , Daniel , Kilcup , Patel , Sharpe

We introduce a mixed-action approach based on CLS ensembles, where a valence $N_f$=2+1+1 Twisted Mass QCD action is combined with the $N_f$=2+1 non-perturbatively O$(a)$-improved Wilson sea sector. We show that for maximally twisted valence…

High Energy Physics - Lattice · Physics 2018-12-05 Andrea Bussone , Sergio Chaves , Gregorio Herdoíza , Carlos Pena , David Preti , José Ángel Romero , Javier Ugarrio

We present a lattice QCD calculation of the heavy-light decay constants f_B and f_Bs performed with Nf=2 maximally twisted Wilson fermions, at four values of the lattice spacing. The decay constants have been also computed in the static…

We develop an implementation for a recently proposed Noisy Monte Carlo approach to the simulation of lattice QCD with dynamical fermions by incorporating the full fermion determinant directly. Our algorithm uses a quenched gauge field…

High Energy Physics - Lattice · Physics 2009-11-07 B. Joo , I. Horvath , K. F. Liu

We consider the renormalisation of lattice QCD operators with one and two covariant derivatives related to the first and second moments of generalised parton distributions and meson distribution amplitudes. Employing the clover fermion…

High Energy Physics - Lattice · Physics 2010-10-28 M. Göckeler , R. Horsley , H. Perlt , P. E. L. Rakow , A. Schäfer , G. Schierholz , A. Schiller

We describe a way to optimize the chiral behavior of Wilson-type lattice fermion actions by studying the low energy real eigenmodes of the Dirac operator. We find a candidate action, the clover action with fat links with a tuned clover…

High Energy Physics - Lattice · Physics 2007-05-23 Thomas DeGrand , Anna Hasenfratz , Tamás G. Kovács

We present a first Wilson twisted mass fermion calculation of the matrix element between pion states of the twist-2 operator, which is related to the the lowest moment < x > of the valence quark parton distribution function in a pion. Using…

High Energy Physics - Lattice · Physics 2009-11-11 S. Capitani , K. Jansen , M. Papinutto , A. Shindler , C. Urbach , I. Wetzorke

This paper presents a formulation of lattice fermions applicable to all quark masses, large and small. We incorporate interactions from previous light-fermion and heavy-fermion methods, and thus ensure a smooth connection to these limiting…

High Energy Physics - Lattice · Physics 2008-11-26 Aida X. El-Khadra , Andreas S. Kronfeld , Paul B. Mackenzie

A lot of effort in lattice simulations over the last years has been devoted to studies of the QCD deconfinement transition. Most state-of-the-art simulations use rooted staggered fermions, while Wilson fermions are affected by large…

High Energy Physics - Lattice · Physics 2011-01-27 Bastian B. Brandt , Owe Philipsen , Hartmut Wittig , Lars Zeidlewicz

Thermodynamics in the strong coupling limit of lattice QCD has features which may be similar to those of continuum QCD, such as a chiral critical end point and a nuclear liquid gas transition. Here I compare the combinatorics of staggered…

High Energy Physics - Lattice · Physics 2014-11-18 Wolfgang Unger
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