Wed·Oct 1, 2003Wednesday·October 1, 2003

1. 01*

   Non-perturbative renormalization of vector and axial vector currents in quenched QCD for a renormalization group improved gauge action

   CP-PACS Collaboration: K. Ide🇯🇵 · S. Aoki🇯🇵 · M. Fukugita🇯🇵 · N. Ishizuka🇯🇵 · Y. Iwasaki🇯🇵 · K. Kanaya🇯🇵 · T. Kaneko🇯🇵 · Y. Kuramashi🇯🇵 · V. Lesk🇯🇵 · M. Okawa🇯🇵 · Y. Taniguchi🇯🇵 · A. Ukawa🇯🇵 · T. Yoshié🇯🇵

   Renormalization constants of vector ($Z_V$) and axial-vector ($Z_A$) currents are determined non-perturbatively in quenched QCD for an RG-improved gauge action and a tadpole-improved clover quark action using the Schrödinger functional method. Meson decay constants $f_{\rho }$ and $f_{\pi }$ show much better scaling when $Z_V$ and $Z_A$ estimated for infinite physical volume are used instead of $Z$-factors from tadpole-improved one-loop perturbation theory.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·2 citations
2. 02*

   Electromagnetic Form Factors with FLIC Fermions

   J.M.Zanotti🇦🇺 · D.B.Leinweber🇦🇺 · A.G.Williams🇦🇺 · J.B.Zhang🇦🇺

   The Fat-Link Irrelevant Clover (FLIC) fermion action provides a new form of nonperturbative O(a) improvement and allows efficient access to the light quark-mass regime. FLIC fermions enable the construction of the nonperturbatively O(a)-improved conserved vector current without the difficulties associated with the fine tuning of the improvement coefficients. The simulations are performed with an O(a^2) mean-field improved plaquette-plus-rectangle gluon action on a 20^3 x 40 lattice with a lattice spacing of 0.128 fm, enabling the first simulation of baryon form factors at light quark masses on a large volume lattice. Magnetic moments, electric charge radii and magnetic radii are extracted from these form factors, and show interesting chiral nonanalytic behavior in the light quark mass regime.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·14 citations
3. 03*

   Chiral Structure in Baryon Magnetic Moments

   R. D. Young🇦🇺 · D. B. Leinweber🇦🇺 · A. W. Thomas🇦🇺

   We highlight recent advances in finite-range regularised chiral effective field theory. Application to baryon magnetic moments show an unambiguous signal of quenched chiral physics in FLIC fermion simulations.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·13 citations
4. 04*

   Numerical study of the equation of state for two flavor QCD at finite density

   S. Ejiri🇩🇪 · C.R. Allton🇬🇧 · S.J. Hands🇬🇧 · O. Kaczmarek🇩🇪 · F. Karsch🇩🇪 · E. Laermann🇩🇪 · C. Schmidt🇩🇪

   We discuss the equation of state for 2 flavor QCD at non-zero temperature and density. Derivatives of $\ln Z$ with respect to quark chemical potential ${\mu }_q$ up to fourth order are calculated, enabling estimates of the pressure, quark number density and associated susceptibilities as functions of ${\mu }_q$ via a Taylor series expansion. It is found that the fluctuations in the quark number density increase in the vicinity of the phase transition temperature and the susceptibilities start to develop a pronounced peak as ${\mu }_q$ is increased. This suggests the presence of a critical endpoint in the $(T,{\mu }_q)$ plane.

   hep-lat0 citations
5. 05*

   Lattice QCD in the epsilon-regime and random matrix theory

   Leonardo Giusti🇨🇭 · Martin Lüscher🇨🇭 · Peter Weisz🇩🇪 · Hartmut Wittig🇩🇪

   In the epsilon-regime of QCD the main features of the spectrum of the low-lying eigenvalues of the (euclidean) Dirac operator are expected to be described by a certain universality class of random matrix models. In particular, the latter predict the joint statistical distribution of the individual eigenvalues in any topological sector of the theory. We compare some of these predictions with high-precision numerical data obtained from lattice QCD for a range of lattice spacings and volumes. While no complete matching is observed, the results agree with theoretical expectations at volumes larger than about 5 fm^4.

   hep-lathep-thJHEP(2003)·127 citations
6. 06*

   Dimensional reduction and a Z(3) symmetric model

   P. Bialas🇵🇱 · A. Morel🇫🇷 · B. Petersson🇩🇪

   We present first results from a numerical investigation of a Z(3) symmetric model based on dimensional reduction.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·2 citations
7. 07*

   Free Meson Spectral Functions on the Lattice

   S. Stickan🇩🇪 · F. Karsch🇩🇪 · E. Laermann🇩🇪 · P. Petreczky🇺🇸

   We present results from an analytic calculation of thermal meson spectral functions in the infinite temperature (free field) limit. We compare spectral functions for various lattice fermion formulations used at present in studies of in-medium properties of hadrons based on the maximum entropy method (MEM). In particular, we will present a new calculation of spectral functions performed with extended quark sources.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·9 citations
8. 08*

   Chiral symmetry restoration in excited hadrons

   L. Ya. Glozman🇦🇹

   The evidence, theoretical justification and implications of chiral symmetry restoration in excited hadrons are presented.

   ↳ hep-phcond-mathep-exhep-lat+1AIP Conf.Proc.(2004)·7 citations
9. 09*

   Lattice-QCD-based Schwinger-Dyson Approach for Chiral Symmetry Restoration at Finite Temperature

   Hideaki Iida🇯🇵 · Makoto Oka🇯🇵 · Hideo Suganuma (Tokyo Inst. Tech.)🇯🇵

   We propose the Schwinger-Dyson (SD) formalism based on lattice QCD, i.e., LQCD-based SD formalism, for the study of dynamical chiral-symmetry breaking in QCD. We extract the kernel function K(p^2) in the SD equation from the lattice data of the quark propagator in the Landau gauge. As remarkable features, we find infrared vanishing and intermediate enhancement of the kernel function K(p^2) in the SD equation. We apply the LQCD-based SD equation to thermal QCD, and calculate the quark mass function at the finite temperature. We find chiral symmetry restoration at the critical temperature T_c \sim 100MeV.

   ↳ hep-phhep-latnucl-thNucl.Phys.B Proc.Suppl.(2004)·2 citations
10. 10*

    The charmed strange meson system

    Wolfgang Lucha🇦🇹 · F. F. Schoberl🇦🇹

    Motivated by the recent surprising discovery of two new meson states with c s-bar quark content but unexpectedly low masses and narrow total decay widths, we work out, in a nonrelativistic potential-model approach developed already some two decades ago, the predictions for the energy levels of the corresponding charm-antistrange quark bound states. In spite of the fact that this simple quark model reproduces the mass spectrum of the previously observed hadrons remarkably well, we are led to the conclusion that, without considerable modifications, both the new states do not fit into this framework.

    ↳ hep-phhep-exhep-latnucl-ex+1Mod.Phys.Lett.A(2003)·39 citations
11. 11*

    Lattice supersymmetry and string phenomenology

    Joel Giedt🇨🇦

    I discuss the usefulness of lattice supersymmetry in relation to string phenomenology. I suggest how lattice results might be incorporated into string phenomenology. I outline difficulties and describe some constructions that contain an exact lattice version of supersymmetry, thereby reducing fine-tuning of the regulator. I mention some problems that occur for these lattices.

    ↳ hep-phhep-lathep-th3 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.