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Related papers: Schr"odinger functional at negative flavour number

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We test the cooling algorithm with gluonic and staggered hadronic spectroscopy on $SU(3)$ gauge field configurations generated with two flavors of staggered dynamical fermions. We find cooling is not reliable as the basis for improved…

High Energy Physics - Lattice · Physics 2009-10-28 Robert G. Edwards , Khalil Bitar , Urs M. Heller , A. D. Kennedy

We determine the fine-tuning of the Yukawa couplings of supersymmetric QCD, discretized on a lattice. We use perturbation theory at one-loop level. The Modified Minimal Subtraction scheme ($\overline{{\rm MS}}$) is employed; by its…

High Energy Physics - Lattice · Physics 2023-11-01 Marios Costa , Herodotos Herodotou

The recently proposed construction of chiral fermions on lattices with boundaries is tested in an interacting theory up to first order of perturbation theory. We confirm that, in the bulk of the lattice, the chiral Ward identities take…

High Energy Physics - Lattice · Physics 2011-07-04 Bjorn Leder

Flavor singlet combinations of quark operators ${\cal{O}}_S^{\Gamma} = \bar{u}\Gamma u + \bar{d}\Gamma d + \bar{s}\Gamma s$ contribute to many important physical observables in the low energy region of QCD. Experimentally one finds the…

High Energy Physics - Lattice · Physics 2007-05-23 S. Güsken

We discuss a 3-flavour lattice QCD action with clover improvement in which the fermion matrix has single level stout smearing for the hopping terms together with unsmeared links for the clover term. With the (tree-level) Symanzik improved…

We present results on the axial, scalar and tensor isovector-couplings of the nucleon from 2+1 flavor lattice QCD with physical light quarks ($m_\pi$ = 135 MeV) in large spatial volume of (10.8 fm)$^3$. The calculations are carried out with…

The phase diagram of the Schwinger model on the lattice with one and two degenerate flavours of Wilson fermions is investigated in the Hartree-Fock approximation. In case of a single flavour (not directly amenable to numerical simulation),…

High Energy Physics - Lattice · Physics 2009-10-28 Ivan Horvath

We test a recently proposed improved lattice-fermion action, the fat link clover action, examining indicators of pathological small-quark-mass lattice artifacts ("exceptional configurations") on quenched lattices of spacing 0.12 fm and…

High Energy Physics - Lattice · Physics 2008-11-26 Mark Stephenson , Carleton DeTar , Thomas DeGrand , Anna Hasenfratz

We extract the next-to-leading-order low-energy constants \bar\ell_3 and \bar\ell_4 of SU(2) chiral perturbation theory, based on precise lattice data for the pion mass and decay constant on ensembles generated by the Wuppertal-Budapest…

High Energy Physics - Lattice · Physics 2013-09-03 Szabolcs Borsanyi , Stephan Durr , Zoltan Fodor , Stefan Krieg , Andreas Schafer , Enno E Scholz , Kalman K Szabo

We compute the hadronic running of the electromagnetic and weak couplings in lattice QCD with $N_{\mathrm{f}}=2+1$ flavors of $\mathcal{O}(a)$ improved Wilson fermions. Using two different discretizations of the vector current, we compute…

In view of the recent excitement about a tension between determinations of f_Ds from experiment and from simulations of lattice QCD with dynamical quarks, we try to clear up the picture of lattice determinations in the continuum limit of…

High Energy Physics - Lattice · Physics 2011-04-04 Jochen Heitger , Andreas Juttner

We compare extensive simulations of QCD with 8 and 12 flavors of degenerate quarks, using the DBW2 gauge action, naive staggered fermions, and the rational hybrid Monte Carlo algorithm. A variety of values of the coupling constant, quark…

High Energy Physics - Lattice · Physics 2010-02-17 Xiao-Yong Jin , Robert D. Mawhinney

The electroweak gauge symmetry is allowed to be spontaneously broken by the strongly interacting vector-like gauge dynamics. When the gauge coupling of a theory runs slowly in a wide range of energy scale, the theory is a candidate for…

High Energy Physics - Lattice · Physics 2010-03-18 N. Yamada , M. Hayakawa , K. -I. Ishikawa , Y. Osaki , S. Takeda , S. Uno

We study the spectra of charmonia, charmed mesons, singly and doubly charmed baryons using Lattice QCD, with 2+1 flavours of fermions. In the case of mesons, we include higher spin states, while for baryons, both positive and negative…

High Energy Physics - Lattice · Physics 2015-06-12 Gunnar Bali , Sara Collins , Paula Pérez-Rubio

We investigate spatial two-point correlation functions of mesonic operators in two-flavor lattice QCD at high temperatures. The simulated temperatures over the range $T \in [147, 330]$ MeV, where the critical temperature is estimated around…

We investigate the continuum spectrum of the SU(2) gauge theory with $N_f=2$ flavours of fermions in the fundamental representation. This model provides a minimal template which is ideal for a wide class of Standard Model extensions…

High Energy Physics - Lattice · Physics 2016-12-07 Rudy Arthur , Vincent Drach , Martin Hansen , Ari Hietanen , Claudio Pica , Francesco Sannino

We perform a pilot study of the perturbative renormalization of a Supersymmetric gauge theory with matter fields on the lattice. As a specific example, we consider Supersymmetric ${\cal N}{=}1$ QCD (SQCD). We study the self-energies of all…

High Energy Physics - Lattice · Physics 2018-04-18 Marios Costa , Haralambos Panagopoulos

The chiral Lagrangian describing the low-energy behavior of N_f=2+1+1 twisted mass lattice QCD is constructed through O(a^2). In contrast to existing results the effects of a heavy charm quark are consistently removed, leaving behind a…

High Energy Physics - Lattice · Physics 2014-09-05 Oliver Baer , Ben Horz

A modified formulation of the Schr\"odinger functional (SF) is proposed. In the continuum it is related to the standard SF by a non-singlet chiral field rotation and therefore referred to as the chirally rotated SF ($\chi$SF). On the…

High Energy Physics - Lattice · Physics 2011-03-21 Stefan Sint

We discuss some large effects of dynamical fermions. One is a cutoff effect, others concern the contribution of multi-pion states to correlation functions and are expected to survive the continuum limit. We then turn to the preparation for…

High Energy Physics - Lattice · Physics 2010-12-13 M. Della Morte , P. Fritzsch , B. Leder , S. Takeda , O. Witzel , U. Wolff , H. Meyer , H. Simma , R. Sommer