@article{78823a5c1f544b5ab1187acc12c235e8,
title = "Variational approach to the Z(2) gauge theory",
abstract = "We study the Z(2) lattice gauge theory with matter fields usinf a variational approach within the hamiltonian formulation. Using all possible asymptotic vacua as candidates for the vacuum at any point of the two-dimensional parameter space, we find a two-phase structure and a line of first-order phase transitions which ends at a critical point. Results are presented for both D = 2 and 3 space dimensions. For D = 2 we calculate the critical indices and find that they coincide with the mean field theory results for ferromagnets.",
author = "D. Horn and E. Katznelson",
note = "Funding Information: We study the Z (2) lattice gauge theory with matter fields using a variational approach within the hamiltonian formulation. Using all possible asymptotic vacua as candidates for the vacuum at any point of the two-dimensional parameter space, we find a two-phase structure and a line of first-order phase transitions which ends at a critical point. Results are presented for both D = 2 and 3 space dimensions. For D = 2 we calculate the critical indices and find that they coincide with the mean field theory results for ferromagnets The Z(2) lattice gauge theory with matter fields received' considerable attention recently because it serves as a useful theoretical laboratory for studying confinement and Higgs phenomena \[1 -4\]. This model exhibits a gauge-screening (GS) phase, in which external charges do not feel the confining force, and a matter-screening (MS) phase in which dynamical confinement takes place. The MS phase includes both conventional confinement and Higgs regions. Monte Carlo calculations have established that there exists a finite line of first-order phase transitions which separates locally the confinement and Higgs regions whenever this is possible \[3\].T his line was recently exhibited also by Kogut \[4\]u, sing a 1IN expansion of Potts models. In this paper we demonstrate the existence of this interesting structure using trial wave functions for the vacuum of this system.in a hamiltonian formulation. We extend the methods of ref. \[2\]t o obtain a better description of the vacuum over finite regions in parameter space. The hamiltonian is defined by ¢' Work supported in part by the Israel Commission for Basic Research and the US-Israel Bi-National Science Foundation (BSF).",
year = "1980",
month = apr,
day = "21",
doi = "10.1016/0370-2693(80)91005-9",
language = "אנגלית",
volume = "91",
pages = "397--400",
journal = "Physics Letters B",
issn = "0370-2693",
publisher = "Elsevier B.V.",
number = "3-4",
}