Physical Sciences and Mathematics Commons^™

The John Muir Newsletter, Winter 2010/2011, The John Muir Center

Muir Center Newsletters, 1981-2015

Page 1 transcription missing

PAGE 2 John Muir Back and Newsletter Going Digital After a year, we are back! Last year we announced that we would become an "occasional" newsletter, projecting two issues per year. We only released one issue this past year. In an age of high cost of reproduction and mailing we have decided to follow the trail of other newsletters by going digital. Those with e mail can continue to receive at no charge the newsletter as part of a web serve list. Simply e mail us at iohnmuir@pacific.edu and we will include you in our future …

Generalized Twisted Quantum Doubles And The Mckay Correspondence, Christopher D. Goff, Geoffrey Mason

College of the Pacific Faculty Articles

We consider a class of quasiHopf algebras which we call generalized twisted quantum doubles. They are abelian extensions H=C[G¯]∗⋈C[G] (G is a finite group, G¯ a homomorphic image, and * denotes the dual algebra), possibly twisted by a 3-cocycle, and are a natural generalization of the twisted quantum double construction of Dijkgraaf, Pasquier and Roche. We show that if G is a subgroup of SU₂(C) then H exhibits an orbifold McKay Correspondence: certain fusion rules of H define a graph with connected components indexed by conjugacy classes of G¯, each connected component being an extended affine Diagram of …

Nonperturbative Qcd Simulations With 2+1 Flavors Of Improved Staggered Quarks, James E. Hetrick, A. Bazavov

All Faculty Articles - School of Engineering and Computer Science

Dramatic progress has been made over the last decade in the numerical study of quantum chromodynamics (QCD) through the use of improved formulations of QCD on the lattice (improved actions), the development of new algorithms, and the rapid increase in computing power available to lattice gauge theorists. In this article simulations of full QCD are described using the improved staggered quark formalism, “asqtad” fermions. These simulations were carried out with two degenerate flavors of light quarks (up and down) and with one heavier flavor, the strange quark. Several light quark masses, down to about three times the physical light quark …

Topological Susceptibility With The Asqtad Action, James E. Hetrick, A. Bazavov

All Faculty Articles - School of Engineering and Computer Science

Chiral perturbation theory predicts that in quantum chromodynamics (QCD), light dynamical quarks suppress the gauge-field topological susceptibility of the vacuum. The degree of suppression depends on quark multiplicity and masses. It provides a strong consistency test for fermion formulations in lattice QCD. Such tests are especially important for staggered fermion formulations that lack a full chiral symmetry and use the "fourth-root" procedure to achieve the desired number of sea quarks. Over the past few years we have measured the topological susceptibility on a large database of 18 gauge field ensembles, generated in the presence of 2+1 flavors of dynamical asqtad …