Fri·Aug 31, 2007Friday·August 31, 2007

1. 01*

   Higher loop renormalization of fermion bilinear operators

   A. Skouroupathis🇨🇾 · H. Panagopoulos (Department of Physics, University of Cyprus)🇨🇾

   We compute the two-loop renormalization functions, in the RI' scheme, of local bilinear quark operators $\bar{\psi }\Gamma \psi$, where $\Gamma$ denotes the Scalar and Pseudoscalar Dirac matrices, in the lattice formulation of QCD. We consider both the flavor non-singlet and singlet operators; the latter, in the scalar case, leads directly to the two-loop fermion mass renormalization, $Z_m$. As a prerequisite for the above, we also compute the quark field renormalization, $Z_{\psi }$, up to two loops. We use the clover action for fermions and the Wilson action for gluons. Our results are given as a polynomial in $c_{SW}$, in terms of both the renormalized and bare coupling constant, in the renormalized Feynman gauge. We also confirm the 1-loop renormalization functions, for generic gauge. A longer write-up of the present work, including the conversion of our results to the MSbar scheme and a generalization to arbitrary fermion representations, can be found in arXiv:0707.2906 .

   hep-latPoS(2007)·2 citations
2. 02*

   Lattice Supersymmetry: Equivalence between the Link Approach and Orbifolding

   Poul H. Damgaard🇩🇰 · So Matsuura🇩🇰

   We examine the relation between supersymmetric lattice gauge theories constructed by the link approach and by orbifolding and show that they are equivalent. We discuss the number of preserved supersymmetries.

   hep-lathep-thJHEP(2007)·49 citations
3. 03*

   Z_3 Polyakov Loop Models and Inverse Monte-Carlo Methods

   Christian Wozar🇩🇪 · Tobias Kaestner🇩🇪 · Sebastian Uhlmann🇩🇪 · Andreas Wipf🇩🇪 · Thomas Heinzl🇬🇧

   We study effective Polyakov loop models for SU(3) Yang-Mills theory at finite temperature. A comprehensive mean field analysis of the phase diagram is carried out and compared to the results obtained from Monte-Carlo simulations. We find a rich phase structure including ferromagnetic and antiferromagnetic phases. Due to the presence of a tricritical point the mean field approximation agrees very well with the numerical data. Critical exponents associated with second-order transitions coincide with those of the Z_3 Potts model. Finally, we employ inverse Monte-Carlo methods to determine the effective couplings in order to match the effective models to Yang-Mills theory.

   hep-latPoS(2007)·2 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.