Mon·Nov 19, 2007Monday·November 19, 2007

1. 01*

   The two flavour Schwinger model: scaling of the scalar condensate

   Kei-ichi Nagai🇩🇪 · Nils Christian🇩🇪 · Karl Jansen🇩🇪 · Beatrix Pollakowski🇩🇪

   We investigate the continuum limit scaling of the scalar condensate in the $N_f=2$ Schwinger model on the lattice. We employ maximally twisted mass Wilson fermions and overlap fermions. We compute the scalar condensate by taking the trace of the propagator (direct method) and by utilizing the integrated Ward-Takahashi identity. While the scalar condensate comes out consistent using these two methods for a given kind of lattice fermions, we find --quite surprisingly-- large discrepancies for the scalar condensate between twisted mass and overlap fermions. These discrepancies are only resolved when using the point split current for twisted mass fermions.

   hep-latPoS(2007)·1 citation
2. 02*

   The 't Hooft vertex revisited

   Michael Creutz🇺🇸

   In 1976 't Hooft introduced an elegant approach towards understanding the physical consequences of the topological structures that appear in non-Abelian gauge theories. These effects are concisely summarized in terms of an effective multi-fermion interaction. These old arguments provide a link between a variety of recent and sometimes controversial ideas including discrete chiral symmetries appearing in some models for unification, ambiguities in the definition of quark masses, and flaws with some simulation algorithms in lattice gauge theory.

   ↳ hep-phhep-latAnnals Phys.(2008)·35 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.