arXiv subjects

Marco Panero

Publications and source records attributed to Marco Panero.

97 records · Page 6Linked to original sources

arXiv2005

On the effective string spectrum of the tridimensional Z(2) gauge model

We study the Z(2) lattice gauge theory in three dimensions, and present high precision estimates for the first few energy levels of the string spectrum. These results are obtained from new numerical data for the two-point Polyakov loop correlation function, which is measured in the 3d Ising spin system using duality. This allows us to perform a stringent comparison with the predictions of effective string models. We find a remarkable agreement between the numerical estimates and the Nambu-Goto predictions for the energy gaps at intermediate and large distances. The precision of our data allows to distinguish clearly between the predictions of the full Nambu-Goto action and the simple free string model up to an interquark distance $r \approx 10/\sqrtσ$. At the same time, our results also confirm the breakdown of the effective picture at short distances, supporting the hypothesis that terms which are not taken into account in the usual Nambu-Goto string formulation yield a non-trivial shift to the energy levels. Furthermore, we discuss the theoretical implications of these results.

hep-lat↗

arXiv2005

Studying glueball masses in non-Abelian LGT with the LW algorithm

We address a study of glueball masses in the confining regime of SU(2) in D=3 using an algorithm inspired by the multi-level scheme. Our method, which exploits the locality of the action to achieve high precision results, is based on a technique already used for compact QED, and generalises it to the non-Abelian case. We discuss the main features of this method, in comparison with other algorithms that have been used in similar studies.

hep-lat↗

arXiv2005

A numerical study of confinement in compact QED

Compact U(1) lattice gauge theory in four dimensions is studied by means of an efficient algorithm which exploits the duality transformation properties of the model. We focus our attention onto the confining regime, considering the interquark potential and force, and the electric field induced by two infinitely heavy sources. We consider both the zero and finite temperature setting, and compare the theoretical predictions derived from the effective string model and the dual superconductor scenario to the numerical results.

hep-lat↗

arXiv2005

Comparing the Nambu-Goto string with LGT results

We discuss a way to evaluate the full prediction for the interquark potential which is expected from the effective Nambu-Goto string model. We check the correctness of the prescription reproducing the results obtained with the zeta function regularization for the first two perturbative orders. We compare the predictions with existing Monte Carlo data for the (2+1) dimensional Z(2), SU(2) and SU(3) gauge theories: in the low temperature regime, we find good agreement for large enough interquark distances, but an increasing mismatch between theoretical predictions and numerical results is observed as shorter and shorter distances are investigated. On the contrary, at high temperatures (approaching the deconfinement transition from below) a remarkable agreement between Monte Carlo data and the expectations from the Nambu-Goto effective string is observed for a wide range of interquark distances.

hep-lat↗

arXiv2003

Effective String Picture for Confining Gauge Theories at Finite Temperature

We study the ``effective string picture'' of confinement, deriving theoretical predictions for the interquark potential at finite temperature. At low temperatures, the leading string correction to the linear confining potential between a heavy quark-antiquark pair is the "Lüscher term''. Assuming a Nambu-Goto effective string action, subleading contributions can be worked out in an analytical way. We also discuss the contribution given by a possible ``boundary term'' in the effective action, and compare these predictions with high precision results from simulations of lattice Z(2) gauge theory in three dimensions, obtained with an algorithm that exploits the duality of the Z(2) gauge model with the Ising spin model.

hep-lat↗

arXiv2003

Effective string picture for confinement at finite temperature: theoretical predictions and high precision numerical results

The effective string picture of confinement is used to derive theoretical predictions for the interquark potential at finite temperature. At short distances, the leading string correction to the linear confining potential between a heavy quark-antiquark pair is the "Lüscher term''. We assume a Nambu--Goto effective string action, and work out subleading contributions in an analytical way. We discuss the contribution given by a possible ``boundary term'' in the effective action, comparing these predictions with results from simulations of lattice $Z_2$ gauge theory in three dimensions, obtained with an algorithm which exploits the duality of the $Z_2$ gauge model with the Ising spin model.

hep-lat↗

arXiv2003

Confinement-deconfinement and universal string effects from random percolation

The 't Hooft criterion leading to confinement out of a percolating cluster of central vortices suggests defining a novel three-dimensional gauge theory directly on a random percolation process. Wilson loop is viewed as a counter of topological linking with the random clusters. Beyond the percolation threshold large Wilson loops decay with an area law and show the universal shape effects due to flux tube fluctuations. Wilson loop correlators define a non-trivial glueball spectrum. The crumbling of the percolating cluster when one periodic direction narrows accounts for the finite temperature deconfinement, which belongs to 2D percolation universality class.

hep-lat↗