Related papers: Casimir Scaling and String Breaking in G(2) Gluody…
Assuming that the Casimir scaling hypothesis is well verified in QCD, masses of glueballs and hybrid gluelumps (gluon with a point-like $c\bar c$ pair) are computed within the rotating string formalism. In our model, two gluons are attached…
A lattice calculation shows that the Casimir scaling hypothesis is well verified in QCD, that is to say that the potential between two opposite color charges in a color singlet is proportional to the value of the quadratic Casimir operator.…
We calculate the string tensions of $k$-strings in SU($N$) gauge theories in both 3 and 4 dimensions. In D=3+1, we find that the ratio of the $k=2$ string tension to the $k = 1$ fundamental string tension is consistent, at the $2 \sigma$…
A detailed study is made of four dimensional SU(2) gauge theory with static adjoint ``quarks'' in the context of string breaking. A tadpole-improved action is used to do simulations on lattices with coarse spatial spacings $a_s$, allowing…
Strongly coupled heterotic $E_8\times E_8$ string theory, compactified to four dimensions on a large Calabi-Yau manifold ${\bf X}$, may represent a viable candidate for the description of low-energy particle phenomenology. In this regime,…
The main part of this paper is to present an updated review of the Casimir energy at zero and finite temperature for the transverse oscillations of a piecewise uniform closed string. We make use of three different regularizations: the…
The potentials between static sources in various representaions in SU(3) are calculated based on the fat-center-vortices model of Faber, Greensite and Olejnik. At intermediate distances, most distributions of the flux within vortices lead…
The vacuum of Yang-Mills theories can be imagined as a magnetically disordered medium with domain structure, with color magnetic flux in each domain quantized in units corresponding to the gauge group center. This model leads to the…
Potentials between two static sources in various representations of the SU(3) gauge group are determined on anisotropic 3+1 dimensional lattices. Strong evidence in favour of "Casimir scaling" is found.
In this work, we consider the London limit of the (2+1)D Georgi-Glashow model with dynamical quarks. Following Polyakov's monopole plasma approach and using dual methods to treat the relevant matter sector, we derive in a clear and…
We discuss the Casimir scaling hypothesis on the nonperturbative force in terms of the dual superconducting picture of the QCD vacuum by calculating the string tensions of flux tubes associated with static charges in various SU(3)…
The potentials and string tensions between static sources in a variety of representations (fundamental, 8, 6, 15-antisymmetric, 10, 27 and 15-symmetric) have been computed by measuring Wilson loops in pure gauge SU(3). The simulations have…
We calculate energies and tensions of closed k-strings in (2+1)-dimensional SU(N) gauge theories with N=4,5,6,8. When we study the dependence of the ground state energy on the string length, we find that it is well described by a Nambu-Goto…
Recent accurate measurements of static potentials between sources in various representations of the gauge group SU(3) performed by G.Bali provide a crucial test of the QCD vacuum models and different approaches to confinement. The Casimir…
Three distinct scales are identified in the excitation spectrum of the gluon field around a static quark-antiquark pair as the color source separation R is varied. The spectrum, with string-like excitations on the largest length scales of…
SU(N) gauge theories, extended with adjoint fermions having periodic boundary conditions, are confining at high temperature for sufficiently light fermion mass $m$. In the high temperature confining region, the one-loop effective potential…
The classic argument by Polyakov showing that monopoles produce confinement in the Higgs phase of the Georgi-Glashow model is generalized to study the spectrum of k-strings. We find that the leading-order low-density approximation yields…
We calculate the Casimir energy for the configuration of two parallel plates coupled to nonabelian gauge fields with a Yang-Mills action. We consider both 2+1 and 3+1 dimensions in the manifestly gauge-invariant formalism we have pursued…
We argue that the approximate ``Casimir scaling'' of the string tensions of higher-representation Wilson loops is an effect due to the finite thickness of center vortex configurations. It is shown, in the context of a simple model of the…
In gauge systems coupled to matter, the static potential flattens out at a scale where the confining string breaks by formation of a dynamical pair of particles. Surprisingly, such a breaking is invisible in Wilson loops even when the…