Fri·Sep 26, 2003Friday·September 26, 2003

1. 01*

   Phase structure of lattice QCD for general number of flavors

   Y. Iwasaki🇯🇵 · K. Kanaya🇯🇵 · S. Kaya🇯🇵 · S. Sakai🇯🇵 · T. Yoshie🇯🇵

   We investigate the phase structure of lattice QCD for the general number of flavors in the parameter space of gauge coupling constant and quark mass, employing the one-plaquette gauge action and the standard Wilson quark action. Performing a series of simulations for the number of flavors $N_F=6$--360 with degenerate-mass quarks, we find that when $N_F\ge 7$ there is a line of a bulk first order phase transition between the confined phase and a deconfined phase at a finite current quark mass in the strong coupling region and the intermediate coupling region. The massless quark line exists only in the deconfined phase. Based on these numerical results in the strong coupling limit and in the intermediate coupling region, we propose the following phase structure, depending on the number of flavors whose masses are less than ${\Lambda }_d$ which is the physical scale characterizing the phase transition in the weak coupling region: When $N_F\ge 17$, there is only a trivial IR fixed point and therefore the theory in the continuum limit is free. On the other hand, when $16\ge N_F\ge 7$, there is a non-trivial IR fixed point and therefore the theory is non-trivial with anomalous dimensions, however, without quark confinement. Theories which satisfy both quark confinement and spontaneous chiral symmetry breaking in the continuum limit exist only for $N_F\le 6$.

   hep-lathep-phPRD(2004)·116 citations
2. 02*

   A perturbative determination of O($a$) boundary improvement coefficients for the Schrödinger Functional coupling at 1-loop with improved gauge actions

   Shinji Takeda🇯🇵 · Sinya Aoki🇯🇵 · Kiyotomo Ide🇯🇵

   We perturbatively determine O($a$) boundary improvement coefficients at 1-loop for the Schrödinger Functional coupling with improved gauge actions. These coefficients are required to implement the 1-loop O($a$) improvement in full QCD simulations for the coupling with the improved gauge actions. To this order, lattice artifacts of the step scaling function (SSF) for each improved gauge action are also investigated. Furthermore, we investigate the effect of the 1-loop O($a$) improvement to the SSF in numerical simulations of the pure SU(3) gauge theory.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·2 citations
3. 03*

   A Perturbative Determination of Mass Dependent $O(a)$ Improvement Coefficients in a Relativistic Heavy Quark Action

   Sinya Aoki🇯🇵 · Yasuhisa Kayaba🇯🇵 · Yoshinobu Kuramashi🇯🇵

   We present the results for a perturbative determination of mass dependent improvement coefficients $\nu$, $r_s$, $c_E$ and $c_B$ in a relativistic heavy quark action, which we have designed to control $m_{Q}a$ errors by extending the on-shell $O(a)$ improvement program to the case of $m_Q\gg {\Lambda }_{\mathrm{QCD}}$, where $m_Q$ is the heavy quark mass. The parameters $\nu$ and $r_s$ are determined from the quark propagator and $c_E$ and $c_B$ are from the on-shell quark-quark scattering amplitude. We show that all the parameters, together with the quark wave function and the mass renormalization factors, are determined free from infrared divergences once their tree level values are properly tuned. Results of these parameters are shown as a function of $m_{Q}a$ for various improved gauge actions.

   hep-latNPB(2004)·45 citations
4. 04*

   Heavy hadrons on an anisotropic lattice

   Justin Foley🇮🇪 · Alan O Cais · Mike Peardon🇮🇪 · Sinead M. Ryan🇮🇪

   Results from simulations of quarkonia and heavy-light mesons on an anisotropic lattice are presented. The improved quark action and action-parameter tuning used in this study are discussed.

   hep-latNucl.Phys.B Proc.Suppl.(2004)·3 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.