With the exception of confinement the three-dimensional Nambu−Jona-Lasinio (NJL3) model incorporates many of the essential properties of QCD. We discuss the critical properties of the model at nonzero temperature T and/or nonzero chemical potential μ. We show that the universality class of the thermal transition is that of the d = 2 classical spin model with the same symmetry. We provide eviden...

We consider the Navier-Stokes equations for viscous compressible heat-conducting fluids with cylindrical symmetry. Our main purpose is to study the boundary layer effect and convergence rates as the shear viscosity μ goes to zero. We show that the boundary layer thickness and a convergence rate are of order O(μ) with 0 < α < 1/2 and O( √ μ) respectively, thus extending the result for isentropic...

We derive analytical expressions for the solid angle subtended by a circular disc at a point source with cosine angular distribution (f(μ) = μ/π) under the sole condition that the disc lies in the half-space illuminated by the source (μ ≥ 0). The expressions are given with reference to two alternative coordinate systems (S and S’), S being such that the z axis is parallel to the symmetry axis o...

We use a random matrix model to study chiral symmetry breaking in QCD at finite chemical potential μ. We solve the model and compute the eigenvalue density of the Dirac matrix on a complex plane. A naive “replica trick” fails for μ 6= 0: we find that quenched QCD is not a simple n → 0 limit of QCD with n quarks. It is the limit of a theory with 2n quarks: n quarks with original action and n qua...

The new gauge boson Z ′ predicted by the strong top dynamical symmetry breaking models has significant contributions to the lepton flavor changing process μ −→ 3e. We consider the bound on the mass of the new gauge boson Z ′ from the experimental value of the branching ratio Br(μ −→ 3e) in the framework of topcolor assisted technicolor models. We find that the precision experimental value of Br...

An approximate Z3 family symmetry is proposed for leptons which results in a neutrino mass matrix with sin 2θatm = 1 and tan 2 θsol = 0.5, but the latter value could easily be smaller. A generic requirement of this approach is the appearance of three Higgs doublets at the electroweak scale, resulting in possibly observable flavor violating leptonic decays, such as μ → eee and μ → eγ. ——————————...

The Higgs mixing term coefficient μ is calculated in the supersymmetric theory which possesses a non-anomalous U(1)R symmetry in the limit of global supersymmetry. In this model, supersymmetry is assumed to be broken by gaugino condensation in the hidden sector when the supergravity effects are turned on. The soft breaking terms in the visible sector and the μ term of order the weak scale are p...

We present results from a lattice Monte Carlo study of the Nambu – Jona-Lasinio model in 3+1 dimensions with a baryon chemical potential μ 6= 0. As μ is increased there is a transition from a chirally-broken phase to relativistic quark matter, in which baryon number symmetry appears spontaneously broken by a diquark condensate at the Fermi surface, implying a superfluid ground state. Finite vol...

A possible mechanism for confinement of color is Dual Superconductivity of the Vacuum 1 2 3. The idea is that magnetic charges condense in the vacuum : the chromoelectric field acting between a q− q̄ pair is channeled by dual Meissner effect into flux tubes with energy proportional to the distance. Flux tubes are indeed observed in lattice simulations , and the corresponding field configurations...

We consider QCD at nonzero temperature and quark density in the limit of a large number of colors, Nc. We suggest that several distinct phases can arise. Two are familiar: a cold phase of confined hadrons, with a pressure ∼ N c , and hot phase of deconfined gluons, with pressure ∼ N c . For cold, dense quarks, in a narrow (∼ 1/N c ) window for the quark chemical potential, μ, there is first a d...