Fri·Sep 28, 2001Friday·September 28, 2001

1. 01*

   Lattice study of the simplified model of M-theory for larger gauge groups

   P. Bialas🇵🇱 · J. Wosiek🇵🇱

   Lattice discretization of the supersymmetric Yang-Mills quantum mechanics is dis cussed. First results of the quenched Monte Carlo simulations, for D=4 and with higher g auge groups (3 <= N <= 8), are presented. We confirm an earlier (N=2) evidence tha t the system reveals different behaviours at low and high temperatures separated by a narrow transiti on region. These two regimes may correspond to a black hole and elementary excitations phases conjectured in the M-theory. Dependence of the "transition temperature" on N is consistent with 't Hooft scaling and shows a smooth saturation of lattice results towards the large N limit. Is not yet resolved if the observed change between the two regimes corresponds to a genuine phase transition or to a gentle crossover . A new, noncompact formulation of the lattice model is also proposed and its advantages are briefly discussed.

   hep-lat3 citations
2. 02*

   Center Dominance Recovered: Direct Laplacian Center Gauge

   M. Faber🇦🇹 · J. Greensite🇺🇸 · S. Olejnik🇸🇰

   We introduce a variation of direct maximal center gauge fixing: the "direct Laplacian" center gauge. The new procedure consists of first fixing to the Laplacian adjoint Landau gauge, followed by overrelaxation to the nearby Gribov copy of the direct maximal center gauge. Certain shortcomings of maximal center gauge, associated with Gribov copies, are overcome in the new gauge, in particular center dominance is recovered.

   hep-latNucl.Phys.B Proc.Suppl.(2002)·8 citations
3. 03*

   Confinement versus color superconductivity: a lattice investigation

   Kurt Langfeld🇩🇪

   High density YM-theory is addressed by means of an effective theory where a Higgs type field corresponds to the diquark order parameter. The effective Higgs theory mimics the Cooper instability at the Fermi surface. After Landau gauge fixing, the theory possesses a global color degree of freedom. Color superconductivity corresponds to a spontaneous breakdown of the residual global color symmetry. Numerical simulations illustrate this mechanism of spontaneously broken global color for the case of the standard electro-weak phase transition and for the case of the transition between the confinement and the Higgs phase, respectively. The latter transition is relevant for the study of diquark condensation.

   hep-lathep-phhep-th9 citations
4. 04*

   Comment on `Analysis of O(p^2) Corrections to <2pi|Q_{7,8}|K>'

   Vincenzo Cirigliano🇦🇹 · Eugene Golowich🇺🇸

   We extend in several respects our earlier work on O(p^2) corrections to matrix elements of the electroweak penguin operator O_{ewp}. First, to facilitate comparison with certain lattice studies we calculate O(p^2) corrections to <pi|O_{ewp}|K> in the SU(3) limit of equal light quark masses. Next, we demonstrate how an apparent disagreement in the literature regarding whether higher order chiral contributions increase or decrease <2pi_{I=2}|O_{ewp}|K> is simply a consequence of how the leading order chiral amplitude is defined. Finally, we address an aspect of the epsilon'/epsilon problem by estimating O(p^2) corrections to recent determinations of <2pi_{I=2}|Q_{7,8}|K> which were carried out in the chiral limit.

   ↳ hep-phhep-latPRD(2002)·25 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.