Fri·Sep 10, 2004Friday·September 10, 2004

1. 01*

   Correlation functions at small quark masses with overlap fermions

   L. Giusti🇫🇷 · P. Hernandez🇪🇸 · M. Laine🇩🇪 · C. Pena🇩🇪 · P. Weisz🇩🇪 · J. Wennekers🇩🇪 · H. Wittig🇩🇪

   We report on recent work on the determination of low-energy constants describing Delta{S}=1 weak transitions, in order to investigate the origins of the Delta{I}=1/2 rule. We focus on numerical techniques designed to enhance the statistical signal in three-point correlation functions computed with overlap fermions near the chiral limit.

   hep-latNucl.Phys.B Proc.Suppl.(2005)·7 citations
2. 02*

   Chiral condensate of lattice QCD with massless quarks from the probability distribution function method

   Xiang-Qian Luo🇨🇳

   We apply the probability distribution function method to the study of chiral properties of QCD with quarks in the exact massless limit. A relation among the chiral condensate, zeros of the Bessel function and eigenvalue of Dirac operator is also given. The chiral condensate in this limit can be measured with small number of eigenvalues of the massless Dirac operator and without any ambiguous mass extrapolation. Results for SU(3) gauge theory with quenched Kogut-Susskind quarks on the $10^4$ lattice are shown.

   hep-lathep-phPRD(2004)·2 citations
3. 03*

   Fluctuations in the vicinity of the phase transition line for two flavor QCD

   S. Ejiri🇩🇪 · C.R. Allton🇬🇧 · M. Doering🇩🇪 · S.J. Hands🇬🇧 · O. Kaczmarek🇩🇪 · F. Karsch🇩🇪 · E. Laermann🇩🇪 · K. Redlich🇵🇱

   We study the susceptibilities of quark number, isospin number and electric charge in numerical simulations of lattice QCD at high temperature and density. 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 $({\mu }_q)$ are calculated up to sixth order. From this Taylor series, the susceptibilities are estimated as functions of temperature and ${\mu }_q$. Moreover, we comment on the hadron resonance gas model, which explains well our simulation results below $T_c$.

   hep-latNucl.Phys.B Proc.Suppl.(2005)·13 citations
4. 04*

   QCD Phase Diagram at small Baryon Densities from Imaginary mu: Status Report

   O. Philipsen🇬🇧 · Ph. de Forcrand🇨🇭

   We summarize our recent results for the (T,mu)-phase diagram of N_f=3 QCD. Finding a strong variation of the critical endpoint mu_c with the quark mass m, we point out that an endpoint within reach of experiment requires fine-tuned quark masses. We further discuss the strategy and first data towards extending our results to the physical N_f=2+1 theory.

   hep-lathep-ph4 citations
5. 05*

   The QCD Phase Diagram at Non-zero Baryon and Isospin Chemical Potentials

   D. Toublan🇺🇸 · B. Klein🇩🇪 · J.J.M. Verbaarschot🇺🇸

   In heavy ion collision experiments as well as in neutron stars, both baryon and isospin chemical potentials are different from zero. In particular, the regime of small isospin chemical potential is phenomenologically important. Using a random matrix model, we find that the phase diagram at non-zero temperature and baryon chemical potential is greatly altered by an arbitrarily small isospin chemical potential: There are two first order phase transitions at low temperature, two critical endpoints, and two crossovers at high temperature. As a consequence, in the region of the phase diagram explored by RHIC experiments, there are two crossovers that separate the hadronic phase from the quark-gluon plasma phase at high temperature.

   hep-latNucl.Phys.B Proc.Suppl.(2005)·3 citations
6. 06*

   Finite Temperature Gauge Theory from the Transverse Lattice

   S. Dalley🇬🇧 · B. van de Sande🇺🇸

   Numerical computations are performed and analytic bounds are obtained on the excited spectrum of glueballs in SU(infinity) gauge theory, by transverse lattice Hamiltonian methods. We find an exponential growth of the density of states, implying a finite critical (Hagedorn) temperature. It is argued that the Nambu-Goto string model lies in a different universality class.

   ↳ hep-phhep-lathep-thPRL(2005)·19 citations
7. 07*

   Regularization of Non-commutative SYM by Orbifolds with Discrete Torsion and SL(2,Z) Duality

   Mithat Unsal🇺🇸

   We construct a nonperturbative regularization for Euclidean noncommutative supersymmetric Yang-Mills theories with four (N= (2,2)), eight (N= (4,4)) and sixteen (N= (8,8)) supercharges in two dimensions. The construction relies on orbifolds with discrete torsion, which allows noncommuting space dimensions to be generated dynamically from zero dimensional matrix model in the deconstruction limit. We also nonperturbatively prove that the twisted topological sectors of ordinary supersymmetric Yang-Mills theory are equivalent to a noncommutative field theory on the topologically trivial sector with reduced rank and quantized noncommutativity parameter. The key point of the proof is to reinterpret 't Hooft's twisted boundary condition as an orbifold with discrete torsion by lifting the lattice theory to a zero dimensional matrix theory.

   ↳ hep-thhep-latJHEP(2005)·15 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.