Tue·Aug 20, 2002Tuesday·August 20, 2002

1. 01*

   Application of the Maximum Entropy Method to the (2+1)d Four-Fermion Model

   C.R. Allton🇬🇧 · J.E. Clowser🇬🇧 · S.J. Hands🇬🇧 · J.B. Kogut🇺🇸 · C.G. Strouthos🇬🇧

   We investigate spectral functions extracted using the Maximum Entropy Method from correlators measured in lattice simulations of the (2+1)-dimensional four-fermion model. This model is particularly interesting because it has both a chirally broken phase with a rich spectrum of mesonic bound states and a symmetric phase where there are only resonances. In the broken phase we study the elementary fermion, pion, sigma and massive pseudoscalar meson; our results confirm the Goldstone nature of the pi and permit an estimate of the meson binding energy. We have, however, seen no signal of sigma -> pi pi decay as the chiral limit is approached. In the symmetric phase we observe a resonance of non-zero width in qualitative agreement with analytic expectations; in addition the ultra-violet behaviour of the spectral functions is consistent with the large non-perturbative anomalous dimension for fermion composite operators expected in this model.

   hep-latPRD(2002)·13 citations
2. 02*

   Monopoles, confinement and the photon propagator in QED${}_3$

   M. N. Chernodub🇷🇺 · E.-M. Ilgenfritz🇯🇵 · A. Schiller🇩🇪

   We study the lattice gauge boson propagator of 3D compact QED in Landau gauge at zero and non-zero temperature. Non-perturbative effects are reflected by the generation of a mass $m$, by an anomalous dimension $\alpha$ and by the photon wave function renormalisation $Z$. These effects can be attributed to monopoles: they are absent in the propagator of the regular part of the gauge field. The rôle of Gribov copies is carefully investigated.

   hep-lathep-phNucl.Phys.B Proc.Suppl.(2003)·1 citation
3. 03*

   The H dibaryon on the lattice

   I. Wetzorke🇩🇪 · F. Karsch🇩🇪

   We present our final results for the mass of the six quark flavor singlet state (J^P=0^+, S=-2) called H dibaryon, which would be the lightest possible strangelet in the context of strange quark matter. The calculations are performed in quenched QCD on (8-24)^3 x 30 lattices with the (1,2) Symanzik improved gauge action and the clover fermion action. Furthermore the fuzzing technique for the fermion fields and smearing of the gauge fields is applied in order to enhance the overlap with the ground state. Depending on the lattice size we observe an H mass slightly above or comparable with the \Lambda\Lambda threshold for strong decay. Therefore a bound H dibaryon state seemed to be ruled out by our simulation.

   hep-latNucl.Phys.B Proc.Suppl.(2003)·37 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.