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We present results of a lattice computation of the matrix elements of the vector and axial-vector currents which are relevant for the semi-leptonic decays $D \rightarrow K$ and $D \rightarrow K^*$. The computations are performed in the…

High Energy Physics - Lattice · Physics 2009-10-28 Juan M. Nieves

A modification to the setup algorithm for the multigrid preconditioner of Wilson fermions in lattice QCD is presented. A larger basis of test vectors than that used in conventional multigrid is calculated by the smoother and truncated by…

High Energy Physics - Lattice · Physics 2025-05-21 Travis Whyte , Andreas Stathopoulos , Eloy Romero

The Hypercube operator determines a variant of the approximate, truncated perfect fermion action. In this pilot study we are going to report on first experiences in dynamical QCD simulations with the Hypercube fermions. We apply this…

High Energy Physics - Lattice · Physics 2008-11-26 Stanislav Shcheredin , Edwin Laermann

This paper describes an approach of using dynamic Structural Equation Modeling (SEM) analysis to estimate the connectivity networks from resting-state fMRI data measured by a multiband EPI sequence. Two structural equation models were…

Neurons and Cognition · Quantitative Biology 2017-04-03 Jiancheng Zhuang

A decomposition of the non-equilibrium stationary state of a quadratic Fermi system influenced by linear baths is obtained and used to establish a simulation protocol in terms of tensor states. The scheme is then applied to examine the…

Quantum Physics · Physics 2021-01-14 Jose Reslen

We present an update on Numerical Stochastic Perturbation Theory projects for Lattice QCD, which are by now run on apeNEXT. As a first issue, we discuss a strategy to tackle finite size effects which can be quite sizeable in the computation…

High Energy Physics - Lattice · Physics 2009-04-14 Francesco Di Renzo , Luigi Scorzato , Christian Torrero

We review simulations of dynamical domain wall fermions at a fixed inverse lattice spacing of 1.73GeV and with pion masses as light as 330MeV and spatial dimensions as large as 2.7fm performed by the RBC and UKQCD collaborations. These…

High Energy Physics - Lattice · Physics 2009-07-30 Peter Boyle , RBC , UKQCD Collaborations

We investigate the spectrum and IR properties of the SU(3) "sextet" model with two Dirac fermions in the two-index symmetric representation via lattice simulations. This model is a prime candidate for a realization of Walking Technicolor,…

High Energy Physics - Lattice · Physics 2017-08-30 Martin Hansen , Vincent Drach , Claudio Pica

We present a quenched lattice calculation of the nucleon isovector vector and axial-vector charges gV and gA. The chiral symmetry of domain wall fermions makes the calculation of the nucleon axial charge particularly easy since the…

High Energy Physics - Lattice · Physics 2019-08-15 Shoichi Sasaki , Kostas Orginos , Shigemi Ohta , Tom Blum

We investigate a variant of hypercubic gauge link smearing where the SU(3) projection is replaced with a normalization to the corresponding unitary group. This smearing is differentiable and thus suitable for use in dynamical fermion…

High Energy Physics - Lattice · Physics 2010-10-27 Anna Hasenfratz , Roland Hoffmann , Stefan Schaefer

We look for the effect of open decay channels on the masses of baryons in unquenched lattice QCD. We apply variational smearing using fuzzed basis states to a staggered nucleon operator. The signal for the s_bar s current in the nucleon is…

High Energy Physics - Lattice · Physics 2007-05-23 Eric B. Gregory , Alan C. Irving , Craig McNeile , Steven Miller , Zbyszek Sroczynski

We present a lattice-QCD based analysis of the nucleon sigma terms using gauge ensembles with $N_f = 2 + 1$ flavors of ${\cal O}(a)$-improved Wilson fermions, with a complete error budget concerning excited-state contaminations, the chiral…

High Energy Physics - Lattice · Physics 2024-01-17 Andria Agadjanov , Dalibor Djukanovic , Georg von Hippel , Harvey B. Meyer , Konstantin Ottnad , Hartmut Wittig

We present results of an ongoing study of two flavour QCD with Wilson fermions at finite temperature. We have used tree level Symanzik improvement in both the gauge and fermion part of the action. The phase diagram was previously determined…

High Energy Physics - Lattice · Physics 2009-10-31 F. Karsch , E. Laermann , M. Oevers , P. Schmidt

We investigate the low-lying eigenvalues of the improved Wilson-Dirac operator in the Schroedinger functional with two dynamical quark flavors. At a lattice spacing of approximately 0.1 fm we find more very small eigenvalues than in the…

High Energy Physics - Lattice · Physics 2009-11-10 M. Della Morte , R. Hoffmann , F. Knechtli , U. Wolff

As a feasibility study for a scaling test we investigate the behavior of algorithms for dynamical fermions in the N_f=2 Schroedinger functional at an intermediate volume of 1 fm^4. Simulations were performed using HMC with two…

High Energy Physics - Lattice · Physics 2009-11-10 Michele Della Morte , Roland Hoffmann , Francesco Knechtli , Ulli Wolff

We report on studies of simple matrix elements from simulations with two flavors of sea quarks, both staggered and Wilson. We show the decay constants of vector and pseudoscalar mesons. The effects of sea quarks are small. These simulations…

High Energy Physics - Lattice · Physics 2015-06-25 The High Energy Monte Carlo Grand Challenge

We investigate the combination of a two-level sampling algorithm with distillation techniques to compute disconnected fermionic correlation functions. The method relies on a factorization of the quark propagator into domain-local…

High Energy Physics - Lattice · Physics 2025-12-12 Lorenzo Barca , Jacob Finkenrath , Stefan Schaefer

We have studied transitions between vector and pseudoscalar mesons using the HISQ action for the valence quarks. We have calculated all of the axial and vector form factors that appear in the decay rate for $D_s \to \phi \ell \nu$ over the…

High Energy Physics - Lattice · Physics 2013-11-28 Gordon Donald , Christine Davies , Jonna Koponen

We simulate two dynamical, mass degenerate light quarks on 16^3x32 lattices with a spatial extent of 2.4 fm using the Chirally Improved Dirac operator. The simulation method, the implementation of the action and signals of equilibration are…

High Energy Physics - Lattice · Physics 2009-11-06 Christof Gattringer , Christian Hagen , C. B. Lang , Markus Limmer , Daniel Mohler , Andreas Schäfer

We present the analysis of isovector axial vector nucleon form factors on a set of $N_f=2+1$ CLS ensembles with $\mathcal O(a)$-improved Wilson fermions and L\"uscher-Weisz gauge action. The set of ensembles covers a pion mass range of…

High Energy Physics - Lattice · Physics 2021-12-02 Dalibor Djukanovic , Georg von Hippel , Jonna Koponen , Harvey B. Meyer , Konstantin Ottnad , Tobias Schulz , Hartmut Wittig