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Related papers: A tmQCD mixed-action approach to flavour physics

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A mixed action composed of valence quark flavours regularized with a fully-twisted tmQCD action and of $N_f=2+1$ flavours of non-perturbatively ${\rm O}(a)$-improved Wilson sea quarks is described. Two procedures for the matching of sea and…

High Energy Physics - Lattice · Physics 2019-03-04 Andrea Bussone , Gregorio Herdoíza , Carlos Pena , David Preti , José Ángel Romero , Javier Ugarrio

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 results for a test of a mixed action approach with Osterwalder-Seiler valence quarks on a Wilson twisted mass sea for the example {\eta}, {\eta}' mesons. Flavour singlet pseudoscalar mesons obtain significant contributions from…

High Energy Physics - Lattice · Physics 2013-11-28 Konstantin Ottnad , Carsten Urbach , Falk Zimmermann

We discuss simulations with different lattice Dirac operators for sea and valence quarks. A goal of such a "mixed" action approach is to probe deeper the chiral regime of QCD by enabling simulations with light valence quarks. This is…

High Energy Physics - Lattice · Physics 2014-11-17 O. Baer , G. Rupak , N. Shoresh

We introduce a lattice QCD mixed action approach that employs Wilson-type quarks in the sea and valence sectors. The sea sector is based on gauge ensembles with $N_{\rm f}=2+1$ flavours of non-perturbatively O($a$)-improved Wilson fermions…

We discuss some of the implications of simulating QCD when the action used for the sea quarks is different from that used for the valence quarks. We present exploratory results for the hadron mass spectrum and pseudoscalar meson decay…

High Energy Physics - Lattice · Physics 2009-11-10 UKQCD Collaboration , K. C. Bowler , B. Joó , R. D. Kenway , C. M. Maynard , R. J. Tweedie

We perform the scale setting procedure of a mixed action setup consisting of valence Wilson twisted mass fermions at maximal twist on CLS ensembles with $N_f=2+1$ flavours of $O(a)$-improved Wilson sea quarks. We determine the gradient flow…

High Energy Physics - Lattice · Physics 2024-01-25 Alejandro Saez , Alessandro Conigli , Julien Frison , Gregorio Herdoíza , Carlos Pena

We explore and compare three mixed action setups with Wilson twisted mass sea quarks and different valence quark actions: (1) Wilson twisted mass, (2) Wilson twisted mass + clover and (3) Wilson + clover. Our main goal is to reduce lattice…

High Energy Physics - Lattice · Physics 2013-08-23 Joshua Berlin , David Palao , Marc Wagner

We present the first results obtained by the UKQCD Collaboration using a non-perturbatively $O(a)$ improved Wilson quark action with two degenerate dynamical flavours.

High Energy Physics - Lattice · Physics 2019-08-14 M. Talevi

We study the phase structure of mixed-action QCD with two Wilson sea quarks and two chiral valence quarks, starting from the chiral lagrangian. A priori, the effective theory allows for a rich phase structure, including a phase with a…

High Energy Physics - Lattice · Physics 2011-10-13 Oliver Baer , Maarten Golterman , Yigal Shamir

We study $\eta$ and $\eta'$ mesons and their mixing angle in a mixed action approach with so-called Osterwalder-Seiler valence quarks on a Wilson twisted mass sea. The gauge configurations have been generated by ETMC for $N_f=2+1+1$…

High Energy Physics - Lattice · Physics 2015-06-02 Konstantin Ottnad , Carsten Urbach , Falk Zimmermann

We discuss a Lattice QCD mixed action investigation employing Wilson maximally twisted mass sea and overlap valence fermions. Using four values of the lattice spacing, we demonstrate that the overlap Dirac operator assumes a point-like…

High Energy Physics - Lattice · Physics 2013-01-15 Krzysztof Cichy , Vincent Drach , Elena Garcia-Ramos , Gregorio Herdoiza , Karl Jansen

We report on our simulations with Neuberger valence fermions on CLS $N_f=2$ configurations with non-perturbatively $O(a)$-improved Wilson sea quarks. We consider the matching of QCD to ChPT in the so called mixed-regime in which the sea…

High Energy Physics - Lattice · Physics 2010-11-18 Fabio Bernardoni , Nicolas Garron , Pilar Hernandez , Silvia Necco , Carlos Pena

Some algorithmic details of our $N_f=2+1$ QCD mixed action simulations with overlap valence and improved Wilson sea quarks are presented.

High Energy Physics - Lattice · Physics 2008-11-26 S. Durr , Z. Fodor , C. Hoelbling , S. D. Katz , S. Krieg , Th. Kurth , L. Lellouch , Th. Lippert , K. K. Szabo , G. Vulvert

We present our first set of results for charm physics, using the mixed-action setup introduced in a companion paper. Maximally twisted Wilson valence fermions are used on a sea of non-perturbatively $O(a)$-improved Wilson fermions, made up…

We explore sea quark effects in the light hadron mass spectrum in a simulation of two-flavor QCD using the nonperturbatively O(a)-improved Wilson fermion action. In order to identify finite-size effects, light meson masses are measured on…

Our charm program uses a mixed action with twisted-mass valence quarks over non-perturbatively improved Wilson sea quarks, in order to study various quantities in a relativistic and manifestly local framework of full QCD. The sea sector…

High Energy Physics - Lattice · Physics 2021-12-07 Julien Frison , Gregorio Herdoiza , Carlos Pena , Jose Angel Romero , Javier Ugarrio

Twisted mass QCD (tmQCD) has been introduced as a solution to the problem of unphysical fermion zero modes in lattice QCD with quarks of the Wilson type. We here argue that O(a) improvement of the tmQCD action and simple quark bilinear…

High Energy Physics - Lattice · Physics 2007-05-23 Roberto Frezzotti , Stefan Sint

Lattice QCD calculations with different staggered valence and sea quarks can be used to improve determinations of quark masses, Gasser-Leutwyler couplings, and other parameters relevant to phenomenology. We calculate the masses and decay…

High Energy Physics - Lattice · Physics 2017-09-06 Jon A. Bailey , Hyung-Jin Kim , Jongjeong Kim , Weonjong Lee , Boram Yoon

We show that maximally twisted mass fermions can be employed to regularize on the lattice the fully unquenched QCD+QED theory with vanishing $\theta$-term. We discuss how the critical mass of the up and down quarks can be conveniently…

High Energy Physics - Lattice · Physics 2016-12-08 Roberto Frezzotti , Giancarlo Rossi , Nazario Tantalo
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