Square Symanzik action to one-loop order

We present the one-loop coefficients for an alternative Symanzik improved lattice action with gauge groups SU(2) or SU(3).Comment: 3 pages, latex, 1 table, no figure

A new approach to instanton calculations in the O(3) nonlinear sigma model

We construct all instantons in the \nlsig\ on a cylindrical space-time, known not to exist on a finite time interval. The scale parameter, $\rho$, is related to the boundary condition in time. This may cure the $\rho\rightarrow0$ divergent instanton gas, through a proper inclusion of in and out states in the path integral.Comment: References added and corrected. Contribution to Lattice'94, 27 Sep - 1 Oct 1994, Bielefeld, Germany. 3 pages PostScript, uuencoded compresse

White spot syndrome virus envelope protein VP28 is involved in the systemic infection of shrimp

AbstractWhite spot syndrome virus (WSSV) is a large DNA virus infecting shrimp and other crustaceans. The virus particles contain at least five major virion proteins, of which three (VP26, VP24, and VP15) are present in the rod-shaped nucleocapsid and two (VP28 and VP19) reside in the envelope. The mode of entry and systemic infection of WSSV in the black tiger shrimp, Penaeus monodon, and the role of these proteins in these processes are not known. A specific polyclonal antibody was generated against the major envelope protein VP28 using a baculovirus expression vector system. The VP28 antiserum was able to neutralize WSSV infection of P. monodon in a concentration-dependent manner upon intramuscular injection. This result suggests that VP28 is located on the surface of the virus particle and is likely to play a key role in the initial steps of the systemic WSSV infection in shrimp

Improved action and Hamiltonian in finite volumes

We introduce a new Symanzik improved action by adding a 2x2 plaquette in such a way that the Feynman rules in the covariant gauge simplify. We call this the square Symanzik action. Some comparisons with the continuum and the standard Wilson action are made in intermediate volumes, where mass ratios are accurately known and the precise amount of improvement can be determined. Ratios of the Lambda parameters will be presented, as well as partial results for the one-loop improvement coefficients. We discuss some of the intricacies that arise because of violations of unitarity at the scale of the cutoff. In particular we show how a field redefinition in the zero-momentum effective action allows one to remove scaling violations linear in the lattice spacing.Comment: 6 pages, 2 figures. Talk presented at LATTICE96(improvement

Computation of the one-loop Symanzik coefficients for the square action

We compute the one-loop coefficients for an alternative Symanzik improved pure gauge SU{N} lattice action (N=2 and N=3). For the standard Symanzik improved action we confirm previous results by L\"{u}scher and Weisz.Comment: 45 pages, LaTeX, includes library.ps for generating Feynman diagram