Related papers: Pad\'e approximation and glueball mass estimates i…
We compute from lattice QCD in the valence (quenched) approximation the partial decay widths of the lightest scalar glueball to pairs of pseudoscalar quark-antiquark states. These predictions and values obtained earlier for the scalar…
The gluon propagator in Landau gauge is calculated in quenched QCD on a large (32^3X64) lattice at beta=6.0. In order to assess finite volume and finite lattice spacing artefacts, we also calculate the propagator on a smaller volume for two…
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.
We consider (1+1)-dimensional QCD coupled to scalars in the adjoint representation of the gauge group SU($N$). This model results from dimensional reduction of the (2+1)-dimensional pure glue theory. In the large-N limit we study the…
We study whether the pseudoscalar glueball mass in full QCD can differ from the prediction of quenched lattice calculations. Using properties of the correlator of the vacuum topological susceptibility we derive an expression for the upper…
The propagator of a physical degree of freedom ought to obey a K\"{a}ll\'{e}n-Lehmann spectral representation, with positive spectral density. The latter quantity is directly related to a cross section based on the optical theorem. The…
We evaluate the infinite volume, continuum limit of glueball masses in the valence (quenched) approximation to lattice QCD. For the lightest states with $J^{PC}$ of $0^{++}$ and $2^{++}$, we obtain $m_0 = 1340 \pm 160$ MeV and $m_2 = 1900…
We briefly review the computational strategy we have recently introduced for computing glueball masses and matrix elements, which achieves an exponential reduction of statistical errors compared to standard techniques. The global symmetries…
Recently there has been a notable progress in the study of glueball states in lattice gauge theories, in particular extrapolating their spectrum to the limit of large number of colors $N$. In this note we compare the large $N$ lattice…
We study pure SU(3) gauge theory on a large lattice, using Schrodinger's equation. Our approximate solution uses a basis of roughly 1000 states. Gauge invariance is recovered when the color content of the ground state is extrapolated to…
Starting from the lattice Landau gauge gluon and ghost propagator data we use a sequence of Pad\'e approximants, identify the poles and zeros for each approximant and map them into the analytic structure of the propagators. For the Landau…
We study a pure gluon plasma in the context of quasiparticle models, where the plasma is considered as an ideal gas of massive bosons. In order to reproduce SU(3) gauge field lattice data within such a framework, we review briefly the…
We introduce a new numerical technique to compute mass spectra, based on difference method and on a new gauge fixing procedure. We show that the method is very effective by test runs on a $SU(2)$ lattice gauge theory.
The multi-level algorithm allows, at least for pure gauge theories, reliable measurement of exponentially small expectation values. The implementation of the algorithm depends strongly on the observable one wants to measure. Here we report…
In this paper we explore the large N limit of the glueball mass spectrum for 2+1 dimensional pure gauge theory. We employ Hamiltonian lattice gauge theory (LGT) and analytic variational techniques to calculate glueball masses for finite…
We use an effective low energy field theory to describe the coupling between glueballs and mesons as an analog of the quenched approximation in lattice QCD. This allows us to study the temperature dependence of mesonic screening masses at…
Results from a calculation of the low-lying glueball spectrum of pure-gauge SU(3) are used as a test of the effectiveness of improved discretisation schemes in reducing finite spacing errors. Glueball masses are extracted from simulations…
We take a new look at plaquette-plaquette correlators in 4d compact U(1) lattice gauge theory which are separated in time, both in the confined and the deconfined phases. From the behaviour of these correlators we extract glueball masses in…
Pad\'e approximants are employed in order to study the analytic structure of the four-dimensional SU(2) Landau-gauge gluon and ghost propagators in the infrared regime. The approximants, which are model independent, are used as fitting…
The estimation of the K\"all\'en-Lehmann spectral density from gauge invariant lattice QCD two point correlation functions is proposed, and explored via an inversion strategy based on Tikhonov regularisation. We test the method on a mesonic…