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Related papers: Some remarks on O(a) improved twisted mass QCD

200 papers

We present physics results from simulations of QCD using $N_f = 2$ dynamical Wilson twisted mass fermions at the physical value of the pion mass. These simulations were enabled by the addition of the clover term to the twisted mass quark…

The vacuum polarization tensor and the corresponding vacuum polarization function are the basis for calculations of numerous observables in lattice QCD. Examples are the hadronic contributions to lepton anomalous magnetic moments, the…

High Energy Physics - Lattice · Physics 2015-03-24 Florian Burger , Grit Hotzel , Karl Jansen , Marcus Petschlies

We present a lattice calculation of the vector form factor of the pion for two flavours of non-perturbatively O(a) improved Wilson fermions. For the measurements we utilise the CLS ensembles which include various lattice spacings and pion…

High Energy Physics - Lattice · Physics 2011-09-02 Bastian B. Brandt , Andreas Juttner , Hartmut Wittig

We non-perturbatively determine the renormalization constant and the improvement coefficients relating the renormalized current and subtracted quark mass in O(a) improved two-flavour lattice QCD. We employ the Schr\"odinger functional…

High Energy Physics - Lattice · Physics 2010-10-06 Patrick Fritzsch , Jochen Heitger , Nazario Tantalo

We calculate pion mass, pion decay constant, PCAC quark mass and nucleon mass in two flavour lattice QCD with unimproved Wilson fermion and gauge actions. Simulations are performed using DD-HMC algorithm at two lattice spacings and two…

High Energy Physics - Lattice · Physics 2015-06-12 Abhishek Chowdhury , Asit K. De , Sangita De Sarkar , A. Harindranath , Jyotirmoy Maiti , Santanu Mondal , Anwesa Sarkar

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 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

We present an improved analysis of our lattice data for the $\eta$--$\eta'$ system, including a correction of the relevant correlation functions for residual topological finite size effects and employing consistent chiral and continuum…

High Energy Physics - Lattice · Physics 2018-03-28 Konstantin Ottnad , Carsten Urbach

We present an exploratory study of leading isospin breaking effects in mesonic masses using $O(a)$ improved Wilson fermions. Isospin symmetry is explicitly broken by distinct masses and electric charges of the up and down quarks. In order…

High Energy Physics - Lattice · Physics 2018-04-18 Andreas Risch , Hartmut Wittig

The $B_K$ parameter is computed in quenched lattice QCD with Wilson twisted mass fermions. Two variants of tmQCD are used; in both of them the relevant $\Delta S = 2$ four-fermion operator is renormalised multiplicatively. The…

High Energy Physics - Phenomenology · Physics 2008-11-26 P. Dimopoulos , J. Heitger , F. Palombi , C. Pena , S. Sint , A. Vladikas

Leptoquarks (LQs) provide very promising solutions to the tensions between the experimental measurements and the SM predictions of $b\to s\ell^+\ell^-$ and $b\to c\tau\nu$ processes. In this case the LQ masses are in general at the TeV…

High Energy Physics - Phenomenology · Physics 2019-03-13 Jason Aebischer , Andreas Crivellin , Christoph Greub

We report results for the interaction measure, pressure and energy density for nonzero temperature QCD with 2+1 flavors of improved staggered quarks. In our simulations we use a Symanzik improved gauge action and the Asqtad $O(a^2)$…

High Energy Physics - Lattice · Physics 2008-11-26 C. Bernard , T. Burch , C. DeTar , Steven Gottlieb , L. Levkova , U. M. Heller , J. E. Hetrick , R. Sugar , D. Toussaint

We describe and test a method known in the literature as low mode averaging to improve Euclidean two-point functions in lattice QCD using the low-lying eigenmodes of the Wilson-Dirac operator D. The contribution from the low modes is…

High Energy Physics - Lattice · Physics 2011-04-20 Gunnar Bali , Luca Castagnini , Sara Collins

Quenched lattice QCD calculations with Wilson-type fermions at small quark masses are impeded by exceptional configurations. We show how this problem can be resolved in a practicable way without changing the physics in the chiral limit.

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , A. Hoferichter , R. Horsley , D. Pleiter , P. Rakow , G. Schierholz , P. Stephenson

Lattice QCD using fermions whose Dirac operator obeys the Ginsparg-Wilson relation, is perhaps the best known formulation of QCD with a finite cutoff. It reproduces all the low energy QCD phenomenology associated with chiral symmetry at…

High Energy Physics - Lattice · Physics 2016-08-25 Shailesh Chandrasekharan

We give a general introduction and discussion of the issues involved in using the twisted mass formulation of lattice fermions in the context of disconnected loop calculations, including a short orientation on the present experimental…

High Energy Physics - Lattice · Physics 2007-05-23 Walter Wilcox , Dean Darnell , Ron Morgan , Randy Lewis

We present recent results in unquenched lattice QCD with two degenerate light sea quarks using the truncated determinant approximation (TDA). In the TDA the infrared modes contributing to the quark determinant are computed exactly up to…

High Energy Physics - Lattice · Physics 2009-11-07 A. Duncan , E. Eichten , J. Yoo

We perform a lattice QCD study of the $\rho$ meson decay from the $N_f=2+1$ full QCD configurations generated with a renormalization group improved gauge action and a non-perturbatively $O(a)$-improved Wilson fermion action. The resonance…

High Energy Physics - Lattice · Physics 2011-11-03 N. Ishizuka , for PACS-CS Collaboration

We present the first study of the light hadron spectrum and decay constants for quenched QCD using an O(a)-improved nearest-neighbour Wilson fermion action at \beta=6.2. We compare the results with those obtained using the standard Wilson…

Results for the equation of state in 2+1 flavor QCD at zero net baryon density using the Highly Improved Staggered Quark (HISQ) action by the HotQCD collaboration are presented. The strange quark mass was tuned to its physical value and the…

High Energy Physics - Lattice · Physics 2019-08-13 Tanmoy Bhattacharya