Fri·Nov 18, 2005Friday·November 18, 2005

1. 01*

   An insight on the Proof of Orientifold Planar Equivalence on the Lattice

   Agostino Patella🇮🇹

   In a recent paper, Armoni, Shifman and Veneziano (ASV) gave a formal non-perturbative proof of planar equivalence between the bosonic sectors of SU(N) super Yang-Mills theory and of a gauge theory with a massless quark in the antisymmetric two-indexes representation. In the case of three colors, the latter theory is nothing but one-flavor QCD. Numerical simulations are necessary to test the validity of that proof and to estimate the size of 1/N corrections. As a first step towards numerical simulations, I will give a lattice version of the ASV proof of orientifold planar equivalence in the strong-coupling and large-mass phase.

   hep-latPRD(2006)·15 citations
2. 02*

   Towards measuring the eta' mass with N_f=2+1 staggered fermions

   Eric B. Gregory🇬🇧 · Alan Irving🇬🇧 · Craig McNeile🇬🇧 · Steven Miller🇬🇧 · Zbyszek Sroczynski🇬🇧

   Because the propagators of flavor-singlet states incorporate disconnected diagrams, they are uniquely sensitive to any differences in the actions governing sea and valence fermions on the lattice. As such, they present an important test of the validity of the ``fourth-root trick'' in the staggered fermion formulation. The pseudoscalar's relationship to topological charge also makes it of theoretical interest. We present preliminary results from our measurements of flavor-singlet pseudoscalar mesons on 2+1 flavor Asqtad lattices, and discuss some strategies for improving the signal-to-error ratio of disconnected singlet correlators.

   hep-latNucl.Phys.B Proc.Suppl.(2006)·1 citation
3. 03*

   Mass gap in a Yang-Mills theory in the strong coupling limit

   Marco Frasca🇮🇹

   We prove that in the limit of the coupling going to infinity a Yang-Mills theory is equivalent to a $\lambda {\varphi }^4$ theory with the dynamics ruled just by a homogeneous equation. This gives explicitly the Green function and the mass spectrum proving that such gauge theories are confining. The scalar glueball spectrum is then proven to be in fair agreement with lattice QCD computations but giving a different ground state coinciding with the $f_0(600)$ light unflavored meson.

   ↳ hep-thhep-lathep-phmath-ph+12 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.