arXiv subjects

Colin Morningstar

Publications and source records attributed to Colin Morningstar.

96 records · Page 6Linked to original sources

arXiv1996

Improved gluonic actions on anisotropic lattices

The use of novel perturbatively-improved gluonic actions on anisotropic lattices in which the temporal spacing is much smaller than that in the spatial directions is discussed. Such actions permit more efficient measurements of noisy correlation functions, such as glueball correlators, on coarse lattices. A derivation of these actions at tree-level is outlined; mean-field link renormalization plays a crucial role in their construction. Results for the low-lying glueball masses and the heavy-quark potential are presented.

hep-lat↗

arXiv1996

Glueballs from Improved Lattice Actions

The low-lying glueball masses and the hadronic scale $r_0$ are computed in lattice SU(3) gauge theory with the aim of establishing the effectiveness of the improved action approach in removing finite-spacing artifacts. The use of anisotropic lattices in which the temporal spacing is much smaller than that in the spatial directions allows much more efficient glueball mass measurements.

hep-lat↗

arXiv1996

CORE Technology and Exact Hamiltonian Real-Space Renormalization Group Transformations

The COntractor REnormalization group (CORE) method, a new approach to solving Hamiltonian lattice systems, is presented. The method defines a systematic and nonperturbative means of implementing Kadanoff-Wilson real-space renormalization group transformations using cluster expansion and contraction techniques. We illustrate the approach and demonstrate its effectiveness using scalar field theory, the Heisenberg antiferromagnetic chain, and the anisotropic Ising chain. Future applications to the Hubbard and t-J models and lattice gauge theory are discussed.

hep-lat↗

arXiv1995

Lattice Perturbation Theory

Sources of uncertainties in perturbative calculations, tadpole improvement and its role in lattice perturbation theory, and six recent calculations are discussed.

hep-lat↗

arXiv1995

The scalar glueball from a tadpole-improved action

The scalar glueball mass and the string tension are computed in lattice SU(3) gauge theory with the aim of establishing the effectiveness of the improved action approach in removing finite-spacing artifacts.

hep-lat↗

arXiv1994

Core -- a New Method for Solving Hamiltonian Lattice Systems

The COntractor REnormalization group (CORE) approximation, a new method for solving Hamiltonian lattice systems, is introduced. The approach combines variational and contraction techniques with the real-space renormalization group approach and is systematically improvable. Since it applies to lattice systems of infinite extent, the method is suitable for studying critical phenomena and phase structure; systems with dynamical fermions can also be treated. The method is tested using the 1+1-dimensional Ising model.

hep-lat↗