Fri·Oct 28, 2005Friday·October 28, 2005

1. 01*

   Quark-gluon vertex with an off-shell O(a)-improved chiral fermion action

   Huey-Wen Lin🇺🇸

   We perform a study the quark-gluon vertex function with a quenched Wilson gauge action and a variety of fermion actions. These include the domain wall fermion action (with exponentially accurate chiral symmetry) and the Wilson clover action both with the non-perturbatively improved clover coefficient as well as with a number of different values for this coefficient. We find that the domain wall vertex function behaves very well in the large momentum transfer region. The off-shell vertex function for the on-shell improved clover class of actions does not behave as well as the domain wall case and, surprisingly, shows only a weak dependence on the clover coefficient $c_{SW}$ for all components of its Dirac decomposition and across all momenta. Including off-shell improvement rotations for the clover fields can make this action yield results consistent with those from the domain wall approach, as well as helping to determine the off-shell improved coefficient $c_q^{\prime }$.

   hep-latPRD(2006)·23 citations
2. 02*

   Non-perturbatively determined relativistic heavy quark action

   Huey-Wen Lin🇺🇸 · Norman H. Christ🇺🇸

   Preliminary results are presented in a step scaling determination of the coefficients in the relativistic heavy quark action. By matching finite volume, heavy-heavy and heavy-light meson masses, we attempt to determine the four parameters ($m$, $\zeta$, $c_B$ and $c_E$) in the on-shell-improved, heavy quark action. In this report we carry out one step in this program by matching two physically equivalent systems. The first is a fully relativistic calculation using a $24^3\times 48$, $1/a=5.4$ GeV lattice with both the heavy and light quarks treated as domain wall fermions. The second calculation uses at $16^3\times 32$, $1/a=3.6$ GeV lattice, a domain-wall light quark and a heavy quark computed with the relativistic heavy quark action. The four parameters in this heavy quark effective action are then varied to reproduce the mass spectrum from the first calculation. These calculations are carried out in the quenched approximation for a heavy quark mass approximately that of the charmed quark.

   hep-latPoS(2006)·4 citations
3. 03*

   Dual superconducting properties of the QCD vacuum

   A. D'Alessandro🇮🇹 · M. D'Elia🇮🇹

   A consistent description of the confining QCD vacuum as a dual superconductor requires a determination of fundamental parameters such as the superconductor correlation length $\xi$ and the field penetration depth $\lambda$, which determine whether the superconductor is of type I or type II. We illustrate preliminary results of a lattice determination of $\xi$ for the case of pure Yang-Mills with two colors, obtained by measuring the temporal correlator of a disorder parameter detecting dual superconductivity.

   hep-latNucl.Phys.B Proc.Suppl.(2007)·2 citations
4. 04*

   Full determination of the CKM matrix using recent results from lattice QCD

   Masataka Okamoto🇯🇵

   A full determination of the CKM matrix using recent results from lattice QCD is presented. To extract the CKM matrix in a uniform fashion, I exclusively use results from unquenched lattice QCD as the theory input for nonperturbative QCD effects. All 9 CKM matrix elements and all 4 Wolfenstein parameters are obtained from results for gold-plated quantities, which include semileptonic decay form factors and leptonic decay constants of B, D and K mesons, and B^0-\bar{B}^0 and K^0-\bar{K}^0 mixing amplitudes.

   hep-lathep-phPoS(2006)·154 citations
5. 05*

   Simulations of Cold Electroweak Baryogenesis

   Anders Tranberg🇬🇧 · Jan Smit🇳🇱

   Cold Electroweak Baryogenesis is an attempt to explain the cosmological baryon asymmetry using only a minimal extension of the Standard Model. The relevant processes take place out of thermal equilibrium and are non-perturbative, and so must be studied using full, real-time lattice simulations. We present new results on the dependence on CP-violation and the Higgs-to-W-mass ratio

   hep-latPoS(2006)·0 citations
6. 06*

   Dirac eigenvalue correlations in quenched QCD at finite density

   James C. Osborn🇺🇸 · Tilo Wettig🇩🇪

   We compare eigenvalue correlations of the Dirac operator with a chemical potential obtained from lattice simulations of quenched QCD with analytic predictions obtained from chiral effective theories in the zero-momentum limit. By comparing the density and two-point correlation function we show that the analytic results agree with QCD at low energies. We also examine the scale (Thouless energy) up to which the zero-momentum approximation is valid.

   hep-latPoS(2006)·21 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.