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Related papers: Three-Loop Results in QCD with Wilson Fermions

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We have determined the non-perturbative O(a)-improvement coefficient c_sw for four flavors of Wilson quarks with the plaquette gauge action in a range of beta >= 5. The data are fitted with several Pade approximation formulae to get an…

High Energy Physics - Lattice · Physics 2014-11-20 Fatih Tekin , Rainer Sommer , Ulli Wolff

We calculate one-loop renormalization factors of three-quark operators, which appear in the low energy effective Lagrangian of the nucleon decay, for $O(a)$-improved quark action and gauge action including six-link loops. This calculation…

High Energy Physics - Lattice · Physics 2016-12-28 S. Aoki , Y. Kuramashi , T. Onogi , N. Tsutsui

We review our results for lattice QCD at finite temperature and density from analytical and numerical calculations with Wilson fermions and overlap fermions.

High Energy Physics - Lattice · Physics 2009-04-25 Xiang-Qian Luo , He-Sheng Chen , Xiao-Lu Yu

We report on our study of two-flavor full QCD on anisotropic lattices using $O(a)$-improved Wilson quarks coupled with an RG-improved glue. The bare gauge and quark anisotropies corresponding to the renormalized anisotropy $\xi=a_s/a_t = 2$…

We present a scaling study of lattice QCD with O(a) improved Wilson fermions and a chirally twisted mass term. In order to get precise results with a moderate computational effort, we have considered a system of physical size of 0.75^3 *…

High Energy Physics - Lattice · Physics 2009-10-31 M. Della Morte , R. Frezzotti , J. Heitger , S. Sint

The one-loop determination of the coefficient $c_\text{SW}$ of the Wilson quark action has been useful to push the leading cut-off effects for on-shell quantities to $\mathcal{O}(\alpha^2 a)$ and, in conjunction with non-perturbative…

High Energy Physics - Lattice · Physics 2024-02-16 Maximilian Ammer , Stephan Durr

QCD is investigated at finite temperature using Wilson fermions in the fixed scale approach. A 2+1 flavor stout and clover improved action is used at four lattice spacings allowing for control over discretization errors. The light quark…

Lattice QCD calculations using gauge smearing for fermion kernels are computationally efficient. Hypercubic blocking (nHYP smearing) has been shown to reduce scaling errors. In this work we use an improved action for $N_f=2$ QCD, based on…

High Energy Physics - Lattice · Physics 2020-11-18 Hossein Niyazi , Andrei Alexandru , Frank X. Lee , Ruairí Brett

We compute the effective hamiltonian for non-leptonic |Delta F| = 1 decays in the standard model including next-to-next-to-leading order QCD corrections. In particular, we present the complete three-loop anomalous dimension matrix…

High Energy Physics - Phenomenology · Physics 2009-09-10 Martin Gorbahn , Ulrich Haisch

We calculate the perturbative value of the Free Energy in Lattice QCD in three dimensions, up to three loops. Our calculation is performed using the Wilson formulation for gluons in SU(N) gauge theories. The Free Energy is directly related…

High Energy Physics - Lattice · Physics 2009-11-11 H. Panagopoulos , A. Skouroupathis , A. Tsapalis

We study QCD with two flavors of dynamical Wilson fermions at $\beta = 5.5$ and three values of $\kappa$. The corresponding pion masses are 0.375, 0.324 and 0.262 in lattice units, with pion to rho mass ratios of 0.76, 0.71 and 0.62,…

High Energy Physics - Lattice · Physics 2009-10-28 K. M. Bitar , R. G. Edwards , U. M. Heller , A. D. Kennedy

We compute the light hadron mass spectrum at beta=5.7 using the O(a) improved Sheikholeslami-Wohlert (SW) fermion action with two choices of the clover coefficient: the classical value, c=1, and a mean-field or tadpole-improved estimate…

The decay B_s -> mu^+ mu^- in the Standard Model is generated by the well-known W-box and Z-penguin diagrams that give rise to an effective quark-lepton operator Q_A at low energies. We compute QCD corrections of order alpha_s^2 to its…

High Energy Physics - Phenomenology · Physics 2014-03-18 Thomas Hermann , Mikolaj Misiak , Matthias Steinhauser

We compute the electric screening mass in lattice QCD with Wilson fermions at finite temperature and chemical potential to one-loop order, and show that lattice artefacts arising from a finite lattice spacing result in an enhancement of the…

High Energy Physics - Lattice · Physics 2014-11-17 P. Kaste , H. J. Rothe

The improved Wilson quark action - the clover action - is constructed to have smaller discretization errors than the normal Wilson quark action. We test this in a quenched spectroscopy computation on 6 lattice ensembles with spacings from…

High Energy Physics - Lattice · Physics 2007-05-23 Sara Collins , R. G. Edwards , U. M. Heller , John Sloan

Accurate determinations of the physical scale of a lattice action are required to check scaling and take the continuum limit. We present a high statistics study of the static potential for the SU(3) Wilson gauge action on coarse lattices…

High Energy Physics - Lattice · Physics 2009-10-30 R. G. Edwards , U. M. Heller , T. R. Klassen

We present a formula for reducing the rank of Wilson fermions from $4 N_c N_x N_y N_z N_t$ to $4 N_c N_x N_y N_z$ keeping the value of its determinant. We analyse eigenvalues of a reduced matrix and coefficients $C_n$ in the fugacity…

High Energy Physics - Lattice · Physics 2010-12-23 Keitaro Nagata , Atsushi Nakamura

We have redone a recent two-loop computation of the critical mass for Wilson fermions in lattice QCD by evaluating Feynman integrals with the coordinate-space method. We present the results for different types of infrared regularization. We…

High Energy Physics - Lattice · Physics 2009-11-07 Sergio Caracciolo , Andrea Pelissetto , Antonio Rago

We present a real-space renormalization group transformation with continuous scale change to calculate the continuous renormalization group $\beta$ function in non-perturbative lattice simulations. Our method is motivated by the connection…

High Energy Physics - Lattice · Physics 2020-03-10 Anna Hasenfratz , Oliver Witzel

A compact general integral formula is derived from which the fermionic contribution to the one-loop coefficient in the perturbative expansion of the MSbar coupling in powers of the bare lattice coupling can be extracted. It is seen to…

High Energy Physics - Lattice · Physics 2008-11-26 David H. Adams