Wed·Sep 1, 2004Wednesday·September 1, 2004

1. 01*

   Numerical study of the equation of state for two flavor QCD at non-zero baryon density

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

   We discuss the equation of state (EoS) for two 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 pressure, quark number density and associated susceptibilities are estimated as functions of temperature and ${\mu }_q$. 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 $({\mu }_q,T)$ plane. Moreover, we comment on the hadron resonance gas model, which explains well our simulation results below $T_c$.

   hep-lat10 citations
2. 02*

   Lattice Simulations with Chemical Potential

   C. Schmidt🇩🇪

   After giving an overview of recently invented methods for simulating lattice QCD at small mu/T, we discuss some results for bulk thermodynamic quantities of QCD matter coming from those methods. We focus on the transition line and the critical endpoint in the QCD phase diagram.

   hep-lat3 citations
3. 03*

   The locality problem for two tastes of staggered fermions

   B. Bunk🇩🇪 · M. Della Morte🇩🇪 · K. Jansen🇩🇪 · F. Knechtli🇩🇪

   We address the locality problem arising in simulations, which take the square root of the staggered fermion determinant as a Boltzmann weight to reduce the number of dynamical quark tastes from four to two. We study analytically and numerically the square root of the staggered fermion operator as a candidate to define a two taste theory from first principles. Although it has the correct weight, this operator is non-local in the continuum limit. Our work serves as a warning that fundamental properties of field theories might be violated when employing blindly the square root trick. The question, whether a local operator reproducing the square root of the staggered fermion determinant exists, is left open.

   hep-latNucl.Phys.B Proc.Suppl.(2005)·5 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.