Related papers: The quenched glueball spectrum from smeared spectr…
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…
The spectrum of glueballs with quantum numbers $J^\mathsf{PC}=0^{\pm+},2^{\pm+},3^{\pm+},4^{\pm+}$ is calculated in quenched quantum chromodynamics from bound state equations. The input is taken from a parameter-free calculation of two- and…
The lowest-lying glueball masses are computed in SU($N$) gauge theory on a spacetime lattice for constant value of the lattice spacing $a$ and for $N$ ranging from 3 to 8. The lattice spacing is fixed using the deconfinement temperature at…
We expand the treatment of the problem of the extraction of smeared spectral densities from Euclidean correlators introduced in [Phys. Rev. D 99, 094508], providing an alternative which does not rely on the Backus-Gilbert regularization.…
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 appropriate inversion method. As proof of concept the SU(2) glueball spectrum for…
Lattice calculations allow us to probe the low-lying, non-perturbative spectrum of QCD using first principles numerical methods. Here we present the low-lying spectrum in the scalar sector with vacuum quantum numbers including, in fully…
We discuss how to extract the spectroscopy of quantum chromodynamics (QCD) in the pure gauge sector from the Hamiltonian lattice field theory approach. The recently developed truncated eigenvalue equation method is applied to the estimation…
A recently re-discovered variant of the Backus-Gilbert algorithm for spectral reconstruction enables the controlled determination of smeared spectral densities from lattice field theory correlation functions. A particular advantage of this…
We calculate the light `glueball' mass spectrum in N_f=2 lattice QCD using a fermion action that is non-perturbatively O(a) improved. We work at lattice spacings a ~0.1 fm and with quark masses that range down to about half the strange…
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…
The quenched spectrum of glueballs with positive charge parity is calculated from two-body bound state equations. As input, a self-contained solution for the primitively divergent correlation functions from Dyson-Schwinger equations is…
Glueball spectrum is studied using an improved gluonic action on asymmetric lattices in the pure SU(3) gauge theory. The smallest spatial lattice spacing is about $0.08fm$ which makes the extrapolation to the continuum limit more reliable.…
Removing ultraviolet noise from the gauge fields is necessary for glueball spectroscopy in lattice QCD. It is known that the Yang-Mills gradient flow method is an alternative approach instead of link smearing or link fuzzing in various…
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…
Mass ratios of glueballs predicted by the latest Lattice QCD calculations in the quenched approximation agree well with four prime experimental candidates.
The mass spectra of heavy and light mesons is computed within the framework of the relativistic flux tube model. A good agreement with the experimental data is obtained provided that the flux tube contributions, including retardation and…
Lattice simulations currently present the only way to access nonperturbative data in strongly coupled theories from a first principle calculation. However, in supersymmetric theories this valuable tool is not available due to the technical…
We review the calculation of the spectrum of glueball masses in non-supersymmetric Yang-Mills theory using the conjectured duality between supergravity and large N gauge theories. The glueball masses are obtained by solving the supergravity…
The mass of the glueballs is calculated in the B.S. equation framework. Under instantaneous approximation, the wave function of B.S. equations are obtained. The kernel is chosen as the sum of an one-gluon exchange potential, a contact…
We report on our continued efforts to measure the glueball and meson spectra in SU($N$) Yang-Mills theory and QCD with the aim of extrapolating to the large-$N$ limit. In particular, we document the computation of the low-lying SU($6$)…