HEP Lattice·hep-lat
5 papers—4 primary·1 cross-listed·reconstructed*
The status of lattice determinations of quark masses is reviewed (with the exception of m_b). Attempts to extract the low-energy constants in the effective chiral Lagrangian are discussed, with special emphasis on those couplings which are required to test the hypothesis of a massless up-quark. Furthermore, the issue of quenched chiral logarithms is addressed.
I review the basic ideas behind lattice QCD calculations that involve charm and bottom quarks. I report on the progress in getting the correct hyperfine splitting in charmonium from lattice QCD. Some of the basic technology behind numerical lattice QCD calculations is explained by studying some specific examples: computation of the charm quark mass, and the calculation of fB.
Recent lattice QCD calculations of the baryon spectrum are outlined.
I present one-loop perturbative calculations of matching coefficients between matrix elements in continuum regulated QCD and lattice QCD with overlap fermions, with emphasis a recently-proposed variant discretization of the overlap. These fermions have extended (``fat link'') gauge connections. The scale for evaluation of the running coupling constant (in the context of the Lepage-Mackenzie fixing scheme) is also given. A variety of results (for additive mass renormalization, local currents, and some non-penguin four-fermion operators) for naive, Wilson, clover, and overlap actions are shown.
Gerald V. Dunne🇺🇸 · Shinsuke M. Nishigaki🇺🇸
We study the low energy phase structure of SU(2) gauge theories in three-dimensional spacetime, at finite baryon density. The pseudoreality of representations of SU(2) permits an analytic study of a real baryon chemical potential, and the restriction to 3D results in a different global symmetry breaking pattern from the corresponding 4D model studied previously by Kogut et al. We find a second-order phase transition separating the normal phase and the baryon superconducting phase. The chemical potential dependence of condensates and baryon density are computed. We find that the phase structure and the excitation spectrum are essentially the same as in 4D, despite the different symmetry groups, indicating a universality that is rooted in the properties of Riemannian symmetric spaces.
* 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.