Adaptive multigrid algorithm for the lattice Wilson-Dirac operator

We present an adaptive multigrid solver for application to the non-Hermitian Wilson-Dirac system of QCD. The key components leading to the success of our proposed algorithm are the use of an adaptive projection onto coarse grids that preserves the near null space of the system matrix together with a simplified form of the correction based on the so-called γ5-Hermitian symmetry of the Dirac operator. We demonstrate that the algorithm nearly eliminates critical slowing down in the chiral limit and that it has weak dependence on the lattice volume.     

Glass Formation Ability and Kinetics of the Gd55A120Ni25 Bulk Metallic Glass

We report a new bulk glass-forming alloy GdssA12oNi25. The bulk sample of the alloy is prepared in the shape of rods in diameter 2ram by suction casting. The rod exhibits typical amorphous characteristics in the x-ray diffraction pattern, paramagnetic property at 30OK, distinct glass transition and multi-step crystallization behaviour in differential scanning calorimetry traces. The gJass formation ability of the alloy is investigated by using the reduced glass transition temperature Trg and the parameter γ- Kinetics of glass transition and primary crystallization is also studied. The fragility parameter m obtained from the Vogel-Fulcher-Tammann dependence of glass transition temperature Tg on In φ （φ is the heating rate） classifies the bulk metallic glasses into the intermediate category according to Angell＇s classification.     

Finite size scaling and low mass glueballs

We propose finite lattice effects as a probe of the glueball mass spectrum, and give an analysis of the recent SU(2) Monte Carlo data of Brower, Nauenberg and Schalk in terms of a gas of free glueballs. For L⁴ lattices with L = 4, 5, 6 fits are made to ξ(m = 1/aξ) which indicate a rather large effective number of degrees of freedom (i.e. statistical degeneracy where a spin J counts as 2J + 1) from 5 to 15 states. As the degeneracy is increased, the central glueball mass increases from $\text{m = (1.3±0.2)}\text{κ}$ at degeneracy 5 to about $\text{m = (1.9±0.2)}\text{κ}$ at degeneracy 15, relative to the SU(2) string tension $\text{κ}$.     

Regge theory for multiparticle amplitudes

The asymptotic behavior of multiparticle scattering amplitudes is discussed and reviewed with an emphasis on the analytic structure of the amplitudes as a function of the channel invariants. Single and multiple asymptotic limits of the Regge and helicity type are defined and a recipe is given for obtaining the asymptotic behavior of amplitudes in these limits controlled by exchanges of factorizable Regge poles and constrained by analyticity requirements. Applications to inclusive cross sections and the decoupling theorems for a pomeron Regge pole are reviewed as illustrative consequences of unitarity for multi-Regge theory. The present understanding of the relationship of cuts in angular momentum to unitarity is also described and suggestions given for further research. An effort has been made to keep the discussion pedagogical, while at the same time providing an entree to the literature.     

An asymptotically free Reggeon field theory

Renormalization group techniques are used to examine Reggeon field theories with derivative triple Pomeranchuk interactions in accord with the decoupling theorems. The simplest asymptotically free “weak coupling” solution has total cross sections which behave as σ_tot^AB(s) ∽ g_Ag_B?c/log s +…, and the triple Pomeranchuk vertex has a nonsense wrong signature zero asymptotically ～(t?t₁?t₂). Another “strong coupling” solution reproduces the results of Migdal, Polyakov, Ter-Martirosyan, Abarbanel and Bronzan to lowest order in the ?-expansion.     

Synthesis and spectroscopic properties of a new class of strongly fluorescent dipyrrinones

A new, highly fluorescent (Phi(F) > or = 0.8) chromophore has been synthesized in one step from dipyrrinones by reaction with N,N-carbonyldiimidazole to form the 3H,5H-dipyrrolo[1,2-c:2',1'-f]pyrimidine-3,5-dione nucleus.