Wed·Oct 12, 2005Wednesday·October 12, 2005

1. 01*

   The nucleon axial charge in full lattice QCD

   LHPC collaboration: R. G. Edwards🇺🇸 · G.T. Fleming🇺🇸 · Ph. Hagler🇩🇪 · J. W. Negele🇺🇸 · K. Orginos🇺🇸 · A. Pochinsky🇺🇸 · D. B. Renner🇺🇸 · D. G. Richards🇺🇸 · W. Schroers🇩🇪

   The nucleon axial charge is calculated as a function of the pion mass in full QCD. Using domain wall valence quarks and improved staggered sea quarks, we present the first calculation with pion masses as light as 354 MeV and volumes as large as (3.5 fm)^3. We show that finite volume effects are small for our volumes and that a constrained fit based on finite volume chiral perturbation theory agrees with experiment within 7% statistical errors.

   hep-lathep-phnucl-thPRL(2006)·187 citations
2. 02*

   Critical behavior of strongly coupled lattice QCD at finite temperature

   Yasuo Umino🇺🇸

   We study the critical behavior of lattice Quantum Chromodynamics (QCD) in the strong coupling approximation with Kogut-Susskind and Wilson fermions at finite temperature ($T$) and zero chemical potential. Using the Hamiltonian formulation we construct a mean field solution to the equation of motion at finite $T$ and use it to study the elementary thermal excitations and to extract some critical exponents characterizing the observed second order phase transition. We find similar critical behaviors for Kogut-Susskind and Wilson fermions at finite $T$

   hep-lathep-phMod.Phys.Lett.A(2006)·2 citations
3. 03*

   HMC algorithm with multiple time scale integration and mass preconditioning

   K. Jansen🇩🇪 · A. Shindler🇩🇪 · C. Urbach🇩🇪 · U. Wenger🇩🇪

   We describe a new HMC algorithm variant we have recently introduced and extend the published results by preliminary results of a simulation with a pseudo scalar mass value of about 300 MeV. This new run confirms our expectation that simulations with such pseudo scalar mass values become feasible and affordable with our HMC variant. In addition we discuss simulations from hot and cold starts at a pseudo scalar mass value of about 300 MeV, which we performed in order to test for possible meta-stabilities.

   hep-latPoS(2006)·14 citations
4. 04*

   Confinement in QCD: Results and Open Problems

   Adriano Di Giacomo🇮🇹

   Progress is reviewed in the understanding of color confinement .

   hep-latActa Phys.Polon.B(2005)·10 citations
5. 05*

   Scalar glueball and meson spectroscopy in unquenched lattice QCD with improved staggered quarks

   Eric B. Gregory🇬🇧 · Alan C. Irving🇬🇧 · Craig C. McNeile🇬🇧 · Steven Miller🇬🇧 · Zbyszek Sroczynski🇬🇧

   We present results of an exploratory study of singlet scalar states in unquenched QCD using both glueball and meson operators. Results for non-singlet non-strange scalar mesons are also presented. We use Asqtad improved staggered fermions and gauge configurations generated by the MILC collaboration at lattice spacings of .12 and .09 fm. In this formulation, the glueball mass is not significantly different from the quenched value at finite lattice spacing. Significant taste violations are present in the scalar sector. At light quark masses, decay channels complicate the mass determinations. There is some evidence that the non-strange singlet meson lies below the non-singlet meson.

   hep-latPoS(2006)·40 citations
6. 06*

   An upper limit to the electric dipole moment of the neutron from lattice QCD

   B. Alles (INFN Pisa)🇮🇹 · M. D'Elia (U. Genova)🇮🇹 · A. Di Giacomo (U. Pisa)🇮🇹

   A linear increase with the volume of the topological susceptibility can signal spontaneous breaking of parity and time inversion, due to a nonzero vacuum expectation value of the topological charge. Such a breaking would produce a nonzero electric dipole moment of the neutron, d_n. An upper limit to d_n is derived from numerical simulations at increasing volumes.

   hep-latNucl.Phys.B Proc.Suppl.(2007)·3 citations
7. 07*

   Screening of Z(N) monopole pairs in gauge theories

   Ph. de Forcrand (ETH Zurich/CERN)🇨🇭 · C. Korthals-Altes (CTP Marseille)🇫🇷 · O. Philipsen (Univ. Munster)🇩🇪

   The screening of magnetic Z(N)-monopoles and the associated screening length in SU(N) gauge theories are analyzed theoretically, and computed numerically in the 3d SU(2) theory. The nature of the screening excitations as well as their mass have so far remained inconclusive in the literature. Here we show that the screening mass is identical to the lowest J^{PC}_R=0^{++}_+ excitation of the Yang-Mills Hamiltonian with one compact direction with period 1/T, the subscript R referring to parity in this direction. We extend the continuum formulation to one on the lattice, and determine the transfer matrix governing the decay of the spatial monopole correlator at any finite lattice spacing. Our numerical results for SU(2) for the screening mass in the dimensionally reduced (high temperature) theory are compatible with the 0^{++} glueball mass in 3d SU(2).

   ↳ hep-phhep-latNPB(2006)·11 citations
8. 08*

   QCD Phase Transitions in the 1/Nc Expansion

   D. Toublan🇺🇸

   We study the QCD phase diagram at nonzero baryon and isospin chemical potentials using the 1/Nc expansion. We find that there are two phase transitions between the hadronic phase and the quark gluon plasma phase. We discuss the consequences of this result for the universality class of the critical endpoint at nonzero baryon and zero isospin chemical potential.

   ↳ hep-thhep-lathep-phnucl-th5 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.