Quark-Antiquark Forces From SU(2) and SU(3) Gauge Theories on Large Lattices

We present results on the spin-independent quark-antiquark potential in SU(3) gauge theory from a simulation on a 48^3*64 lattice at Beta = 6.8, corresponding to a volume of (1.7 fm)^3. Moreover, a comprehensive analysis of spin- and velocity-dependent potentials is carried out for SU(2) gauge theory, with emphasis on the short range structure, on lattices with resolutions ranging from .02 fm to .04 fm.Comment: 10 pages, uucompressed latex with 5 ps figures, epsf style require

U(1) flux tube profiles from Hamiltonian lattice gauge theory using a random walk ground-state projector

We use a self-guided random walk to solve the ground-state problem of Hamiltonian U(1) pure gauge theory in 2+1 dimensions in the string sector. By making use of the electric-field representation, we argue that the spatial distribution of the electric field can be more easily measured than in ordinary Monte Carlo simulations.Comment: 3 pages, contribution to Lattice 94, uuencoded compressed Postscrip

Cylindrically Symmetric Inhomogeneous Universes with a Cloud of Strings

Cylindrically symmetric inhomogeneous string cosmological models are investigated in presence of string fluid as a source of matter. To get the three types of exact solutions of Einstein's field equations we assume $A = f(x)k(t)$, $B = g(x)\ell(t)$ and $C = h(x)\ell(t)$. Some physical and geometric aspects of the models are discussed.Comment: 9 page

A short distance quark-antiquark potential

Leading terms of the static quark-antiquark potential in the background perturbation theory are reviewed, including perturbative, nonperturbative and interference ones. The potential is shown to describe lattice data at short quark-antiquark separations with a good accuracy.Comment: 4 pages, 2 figures, talk at the NPD-2002 Conference, December 2-6, ITEP, Moscow, references update

The scalar and tensor glueballs in the valence approximation

We evaluate the infinite volume, continuum limit of $0^{++}$ and $2^{++}$ glueball masses in the valence approximation. We find $m_{0^{++}} = 1740 \pm 71$~MeV and $m_{2^{++}} = 2359 \pm 128$~MeV, consistent with the interpretation of $f_0 ( 1710 )$ as the lightest scalar glueball.Comment: (talk presented by A. Vaccarino at Lattice 93) 3 pages of PostScript in uufiles compressed form. IBM-HET-94-

Static three- and four-quark potentials

We present results for the static three- and four-quark potentials in SU(3) and SU(4) respectively. Using a variational approach, combined with multi-hit for the time-like links, we determine the ground state of the baryonic string with sufficient accuracy to test the $Y-$ and $\Delta-$ ans\"atze for the baryonic Wilson area law. Our results favor the $\Delta$ ansatz, where the potential is the sum of two-body terms.Comment: Lattice2001(heavyquark

A comprehensive lattice study of SU(3) glueballs

We present a study of the $SU(3)$ glueball spectrum for all $J^{PC}$ values at lattice spacings down to $a^{-1}=3.73 (6)$ GeV ($\beta=6.4$) using lattices of size up to $32^4$. We extend previous studies and show that the continuum limit has effectively been reached. The number of clearly identified $J^{PC}$ states has been substantially increased. There are no clear signals for spin-exotic glueballs below 3 GeV. A comparison with current experimental glueball candidates is made.Comment: 10 pages including 2 PS figures, Liverpool Preprint: LTH 303, Wuppertal Preprint: WUB 93-1