Tue·Oct 9, 2001Tuesday·October 9, 2001

1. 01*

   A strategy to compute the b-quark mass with non-perturbative accuracy

   Jochen Heitger (Univ. Munster)🇩🇪 · Rainer Sommer (DESY Zeuthen)🇩🇪

   We describe a strategy for a non-perturbative computation of the b-quark mass to leading order in 1/m in the Heavy Quark Effective Theory (HQET). The approach avoids the perturbative subtraction of power law divergencies, and the continuum limit may be taken. First numerical results in the quenched approximation demonstrate the potential of the method with a preliminary result m_b(4GeV)=4.56(2)(7) GeV. In principle, the idea may also be applied to the matching of composite operators or the computation of 1/m corrections in HQET.

   hep-lathep-phNucl.Phys.B Proc.Suppl.(2002)·34 citations
2. 02*

   Finite-size scaling and deconfinement transition in gauge theories

   Roberto Fiore🇮🇹 · Alessandro Papa🇮🇹 · Paolo Provero🇮🇹

   A new method is proposed for determining the critical indices of the deconfinement transition in gauge theories, based on the finite-size scaling analysis of simple lattice operators, such as the plaquette. A precise determination of the critical index $\nu$, in agreement with the prediction of the Svetitsky-Yaffe conjecture, is obtained for SU(3) gauge theory in (2+1)-dimension. Preliminary results for SU(2) in (3+1)-dimension are also given.

   hep-latNucl.Phys.B Proc.Suppl.(2002)·5 citations
3. 03*

   Novel Quantum Monte Carlo Algorithms for Fermions

   Shailesh Chandrasekharan🇺🇸

   Recent research shows that the partition function for a class of models involving fermions can be written as a statistical mechanics of clusters with positive definite weights. This new representation of the model allows one to construct novel algorithms. We illustrate this through models consisting of fermions with and without spin. A Hubbard type model with both attractive and repulsive interactions becomes tractable using the new approach. Precision results in the two dimensional attractive model confirm a superfluid phase transition in the Kosterlitz-Thouless universality class.

   hep-lat1 citation
4. 04*

   The Lattice Fermi Surface

   Simon Hands (U.W. Swansea)🇬🇧

   The Nambu - Jona-Lasinio model in 2+1 dimensions is simulated for non-zero baryon chemical potential with a diquark source term. No evidence for a BCS condensate or gap is seen at high density; rather, critical behaviour with novel exponents is observed, suggesting that 2d superfluidity as first described by Kosterlitz and Thouless is realised, but with the universality class determined by the presence of relativistic fermions.

   hep-latcond-mat.supr-connucl-thNPA(2002)·2 citations
5. 05*

   Branes in the 5D Abelian Higgs Model

   P. Dimopoulos🇬🇷 · K. Farakos🇬🇷 · C. P. Korthals-Altes🇫🇷 · G. Koutsoumbas🇬🇷 · S. Nicolis🇫🇷

   We find 3-brane Higgs and Coulomb phases in the 5D Abelian Higgs Model and determine the transition surfaces that separate them from the usual bulk phases.

   hep-lathep-thNucl.Phys.B Proc.Suppl.(2002)·1 citation
6. 06*

   Improved non-perturbative renormalization without $c_{NGI}$

   Stephen R. Sharpe🇺🇸

   Recently, a method for O(a) improvement of composite operators has been proposed which uses the large momentum behavior of fixed gauge quark and gluon correlation functions (G. Martinelli et al., hep-lat/0106003). A practical problem with this method is that a particular improvement coefficient, $c_{NGI}$, which has a gauge non-covariant form, is difficult to determine. Here I work out the size of the errors made in improvement coefficients and physical quantities if one does not include the $c_{NGI}$ term.

   hep-latNucl.Phys.B Proc.Suppl.(2002)·6 citations
7. 07*

   Lattice QCD at finite isospin density

   J. B. Kogut🇺🇸 · D. K. Sinclair🇺🇸

   We have simulated QCD at a finite chemical potential ${\mu }_I$ for isospin ($I_3$) to probe part of the phase diagram for nuclear matter. Preliminary results suggest that for ${\mu }_I>{\mu }_c$, this theory forms a charged pion condensate which spontaneously breaks $I_3$, and the isospin density is non zero.

   hep-latNucl.Phys.B Proc.Suppl.(2002)·1 citation

* 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.