Thermodynamic properties of a simple, confining model

We study the equilibrium thermodynamics of a simple, confining, DSE-model of 2-flavour QCD at finite temperature and chemical potential. The model has two phases: one characterised by confinement and dynamical chiral symmetry breaking; and the other by their absence. The phase boundary is defined by the zero of the vacuum-pressure difference between the confined and deconfined phases. Chiral symmetry restoration and deconfinement are coincident with the transition being of first order, except for $\mu=0$, where it is second order. Nonperturbative modifications of the dressed-quark propagator persist into the deconfined domain and lead to a dispersion law modified by a dynamically-generated, momentum-dependent mass-scale. This entails that the Stefan-Boltzmann limit for the bulk thermodynamic quantities is attained only for large values of temperature and chemical potential.Comment: 11 pages, LaTeX, epsfig.sty, elsart.st

Temperature, chemical potential and the rho meson

We describe some applications of the Dyson-Schwinger equations at nonzero-(T,mu). Employing a simple model dressed-gluon propagator we determine the boundary of the deconfinement phase transition and the medium dependence of rho-meson properties. We introduce an extension to describe the time-evolution of scalar and vector self energies.Comment: 6 pages, LaTeX with 3 EPS figures; Contribution to the 'International Workshop XXVIII on Gross Properties of Nuclei and Nuclear Excitations', Hirschegg, Austria, 16-22.01.200

Slow solitary waves in multi-layered magnetic structures

The propagation of slow sausage surface waves in a multi-layered magnetic configuration is considered. The magnetic configuration consists of a central magnetic slab sandwiched between two identical magnetic slabs (with equilibrium quantities different from those in the central slab) which in turn are embedded between two identical semi-infinite regions. The dispersion equation is obtained in the linear approximation. The nonlinear governing equation describing waves with a characteristic wavelength along the central slab much larger than the slab thickness is derived. Solitary wave solutions to this equation are obtained in the case where these solutions deviate only slightly from the algebraic soliton of the Benjamin-Ono equation

An Expansion Term In Hamilton's Equations

For any given spacetime the choice of time coordinate is undetermined. A particular choice is the absolute time associated with a preferred vector field. Using the absolute time Hamilton's equations are $- (\delta H_{c})/(\delta q)=\dot{\pi}+\Theta\pi,$+ (\delta H_{c})/(\delta \pi)=\dot{q}$, where$\Theta = V^{a}_{.;a}$is the expansion of the vector field. Thus there is a hitherto unnoticed term in the expansion of the preferred vector field. Hamilton's equations can be used to describe fluid motion. In this case the absolute time is the time associated with the fluid's co-moving vector. As measured by this absolute time the expansion term is present. Similarly in cosmology, each observer has a co-moving vector and Hamilton's equations again have an expansion term. It is necessary to include the expansion term to quantize systems such as the above by the canonical method of replacing Dirac brackets by commutators. Hamilton's equations in this form do not have a corresponding sympletic form. Replacing the expansion by a particle number$N\equiv exp(-\int\Theta d \ta)$and introducing the particle numbers conjugate momentum$\pi^{N}$the standard sympletic form can be recovered with two extra fields N and$\pi^N$. Briefly the possibility of a non-standard sympletic form and the further possibility of there being a non-zero Finsler curvature corresponding to this are looked at.Comment: 10 page

DSE Hadron Phenomenology

A perspective on the contemporary use of Dyson-Schwinger equations, focusing on some recent phenomenological applications: a description and unification of light-meson observables using a one-parameter model of the effective quark-quark interaction, and studies of leptonic and nonleptonic nucleon form factors.Comment: 7 pages, sprocl.sty, epsfig.sty. Contribution to the Proceedings of the Workshop on Light-Cone QCD and Nonperturbative Hadron Physics, Adelaide, Australia, 13-22 Dec 199

Evaluation of Two Systems Used to Extract Alfalfa Weevil Larvae (Coleoptera: Curculionidae) from Alfalfa Samples

A modified Berlese funnel system was developed to extract alfalfa weevil larvae (Hypera postica) from quadrats 30.5 cm on a side. Data from this system were comp.wed with simultaneous data from a hand sorting extraction system. In most instances, the modified Berlese system was as efficient as the hand sorting method and the number of man hours required to process samples by hand was far greater than that required by the Berlese system

On the complexion of pseudoscalar mesons

A strongly momentum-dependent dressed-quark mass function is basic to QCD. It is central to the appearance of a constituent-quark mass-scale and an existential prerequisite for Goldstone modes. Dyson-Schwinger equation (DSEs) studies have long emphasised this importance, and have proved that QCD's Goldstone modes are the only pseudoscalar mesons to possess a nonzero leptonic decay constant in the chiral limit when chiral symmetry is dynamically broken, while the decay constants of their radial excitations vanish. Such features are readily illustrated using a rainbow-ladder truncation of the DSEs. In this connection we find (in GeV): f_{eta_c(1S)}= 0.233, m_{eta_c(2S)}=3.42; and support for interpreting eta(1295), eta(1470) as the first radial excitations of eta(548), eta'(958), respectively, and K(1460) as the first radial excitation of the kaon. Moreover, such radial excitations have electromagnetic diameters greater than 2fm. This exceeds the spatial length of lattices used typically in contemporary lattice-QCD.Comment: 7 pages, 2 figures. Contribution to the proceedings of the "10th International Symposium on Meson-Nucleon Physics and the Structure of the Nucleon (MENU04)," IHEP, Beijing, China, 30/Aug.-4/Sept./0