15784128
Vortex free energies in SO(3) and SU(2) lattice gauge theory
Abstract Lattice gauge theories with gauge groups SO(3) and SU(2) are compared. The free energy of electric twist, an order parameter for the confinement- deconfinement transition which does not rely on centre-symmetry breaking, is measured in both theories. The results are used to calibrate the scale in SO(3).
17022554
Symmetries of discontinuous flows and the dual Rankine–Hugoniot conditions in fluid dynamics
Abstract It has recently been shown that the maximal kinematical invariance group of polytropic fluids, for smooth subsonic flows, is the semidirect product of SL  (2,  R ) and the static Galilei group G . This result purports to offer a theoretical explanation for an intriguing similarity, that was recently observed, between a supernova explosion and a plasma implosion. In this paper we extend this result to discuss the symmetries of discontinuous flows, which further validates the explanation by taking into account shock waves, which are the driving force behind both the explosion and implosion. This is accomplished by constructing a new set of Rankine–Hugoniot conditions, which follow from Noether’s conservation laws. The new set is dual to the standard Rankine–Hugoniot conditions and is related to them through the SL  (2,  R ) transformations. The entropy condition, that the shock needs to satisfy for physical reasons, is also seen to remain invariant under the transformations.
5848161
Potts correlators and the static three-quark potential
We discuss the two- and three-point correlators in the two-dimensional three-state Potts model in the high temperature phase of the model. By using the form factor approach and perturbed conformal field theory methods we are able to describe both the large distance and the short distance behaviours of the correlators. We compare our predictions with a set of high precision Monte Carlo simulations (performed on the triangular lattice realization of the model) finding a complete agreement in both regimes. In particular we use the two-point correlators to fix the various non-universal constants involved in the comparison (whose determination is one of the results of our analysis) and then use these constants to compare numerical results and theoretical predictions for the three-point correlator with no free parameter. Our results can be used to shed some light on the behaviour of the three-quark correlator in the confining phase of the (2 + 1)-dimensional SU(3) lattice gauge theory which is related by dimensional reduction to the three-spin correlator in the high temperature phase of the three-state Potts model. The picture which emerges is that of a smooth crossover between a Δ-type law at short distances and a Y-type law at large distances.
16219757
Monte Carlo Overrelaxation for SU(N) Gauge Theories
The standard approach to Monte Carlo simulations of SU(N) Yang-Mills theories updates successive SU(2) subgroups of each SU(N) link. We follow up on an old proposal of Creutz, to perform overrelaxation in the full SU(N) group instead, and show that it is more efficient.
11272883
Instantons and monopoles in general Abelian gauges
A relation between the total instanton number and the quantum numbers of magnetic monopoles that arise in general Abelian gauges in SU (2) Yang-Mills theory is established. The instanton number is expressed as the sum of the `twists' of all monopoles, where the twist is related to a generalized Hopf invariant. The origin of a stronger relation between instantons and monopoles in the Polyakov gauge is discussed.
9563993
Baryons and confining strings
Abstract The subleading term of the heavy quark potential (the analogue of the Luscher term) is computed in a string model for the case of three quarks. It turns out to be positive in 2+1 dimensions, making the potential nonconcave as a function of the scale for fixed geometry. The results are compared to numerical simulations of the lattice gauge theory.
119528385
Study of the $\gamma p -> \eta p$ reaction with the Crystal Ball detector at the Mainz Microtron(MAMI-C)
Here we correct a factor of 2 missed in one of figures and the corresponding sentence in the text. It does not change any conclusions.
121815841
STATUS OF THE GDH EXPERIMENT ON THE DEUTERON AT MAMI
119971868
Helicity dependence of the gamma p -> N pi channels and multipole analysis in the Delta region
A high-quality double-polarization data set for the helicity dependence of the total and differential cross-sections for both gammap --> Npi channels in the Delta region has been obtained in the framework of the GDH experiment. The experiment, performed at the Mainz microtron MAMI, used a 4pi detection system, a circularly polarized photon beam, and a longitudinally polarized frozen-spin target. These data are included in the database to perform a multipole analysis to determine the properties of the Delta(1232)-resonance. For the resonant Delta(1232) multipoles we find a very good agreement with previous analyses, while the nonresonant ones show significant deviations.