93 research outputs found
A QUDA-branch to compute disconnected diagrams in GPUs
Although QUDA allows for an efficient computation of many QCD quantities, it
is surprinsingly lacking tools to evaluate disconnected diagrams, for which
GPUs are specially well suited. We aim to fill this gap by creating our own
branch of QUDA, which includes new kernels and functions required to calculate
fermion loops using several methods and fermionic regularizations.Comment: 7 pages, 4 figures. Proceedings of the talk given during the code
session of the 31st International Symposium on Lattice Field Theory, July 29
- August 3, 2013, Mainz, Germany. Added a missing reference (number [4]
Meson and Baryon dispersion relations with Brillouin fermions
We study the dispersion relations of mesons and baryons built from Brillouin
quarks on one N_f=2 gauge ensemble provided by QCDSF. For quark masses up to
the physical strange quark mass, there is hardly any improvement over the
Wilson discretization, if either action is link-smeared and tree-level clover
improved. For quark masses in the range of the physical charm quark mass, the
Brillouin action still shows a perfect relativistic behavior, while the Wilson
action induces severe cut-off effects. As an application we determine the
masses of the \Omega_c^0, \Omega_{cc}^+ and \Omega_{ccc}^{++} baryons on that
ensemble.Comment: 16 pages, 9 figures, 4 tables; v2: one Reference added, matches
published versio
Nucleon observables and axial charges of other baryons using twisted mass fermions
We present results on the nucleon scalar, axial and tensor charges, as well
as, on the first moments of the unpolarized, polarized and transversity parton
distributions using and twisted mass fermions. These
include an ensemble that yields the physical value of the ratio of the nucleon
to the pion mass. Results on the axial charges of hyperons and charmed baryons
are also presented for a range of pion masses including the physical one.Comment: Corrected figure 1. Conference Proceedings, 7 pages and 6
figures.Talk presented at the 32nd International Symposium on Lattice Field
Theory - LATTICE 2014, 23-28 June, 2014, Columbia University New York, N
First numerical experiences with overlap fermions based on the Brillouin kernel
Numerical experiences are reported with overlap fermions which employ the Brillouin action as a kernel. After discussing the dispersion relations of both the kernel and the resulting chiral action, some of the physics features are addressed on quenched backgrounds. We find that the overlap with Brillouin kernel is much better localized than the overlap with Wilson kernel. Also a preliminary account is given of the cost of the formulation, in terms of CPU time and memory
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