Physical mechanisms generating spontaneous symmetry breaking and a hierarchy of scales

We discuss the phase transition in 3+1 dimensional lambda Phi^4 theory from a very physical perspective. The particles of the symmetric phase (`phions') interact via a hard-core repulsion and an induced, long-range -1/r^3 attraction. If the phion mass is sufficiently small, the lowest-energy state is not the `empty' state with no phions, but is a state with a non-zero density of phions Bose-Einstein condensed in the zero-momentum mode. The condensate corresponds to the spontaneous-symmetry-breaking vacuum with neq 0 and its excitations ("phonons" in atomic-physics language) correspond to Higgs particles. The phase transition happens when the phion's physical mass m is still positive; it does not wait until m^2 passes through zero and becomes negative. However, at and near the phase transition, m is much, much less than the Higgs mass M_h. This interesting physics coexists with `triviality;' all scattering amplitudes vanish in the continuum limit, but the vacuum condensate becomes infinitely dense. The ratio m/M_h, which goes to zero in the continuum limit, can be viewed as a measure of non-locality in the regularized theory. An intricate hierarchy of length scales naturally arises. We speculate about the possible implications of these ideas for gravity and inflation.Comment: 27 pages plus 2 files of figure

Experimental Characteristics of Dynamical Pseudo Goldstone Bosons

The hypothetical existence of new color interactions, which participate in the spontaneous breaking of the weak-interaction group, will in general lead to relatively light composite pseudo Goldstone bosons. Their production and decay characteristics are analyzed to be close to, yet actually distinguishable from, those of the elementary Higgs bosons of the Weinberg-Salam model

Dirac neutrino magnetic moment and a possible time evolution of the neutrino signal from a supernova

We analyze the influence of neutrino helicity conversion, $\nu_L \to \nu_R$, on the neutrino flux from a supernova caused by the interaction of the Dirac neutrino magnetic moment with a magnetic field. We show that if the neutrino has a magnetic moment in the interval $10^{-13} \, \mu_{\rm B} < \mu_\nu < 10^{-12} \, \mu_{\rm B}$ and provided that a magnetic field of $\sim 10^{13} - 10^{14}$ G exists in the supernova envelope, a peculiar kind of time evolution of the neutrino signal from the supernova caused by the resonance transition $\nu_L \to \nu_R$ in the magnetic field of the envelope can appear. If a magnetar with a poloidal magnetic field is formed in a supernova explosion, then the neutrino signal could have a pulsating behavior, i.e., a kind of a neutrino pulsar could be observed, when it rotates around an axis that does not coincide with its magnetic moment and when the orientation of its rotation axis is favourable for our observation.Comment: 9 pages, LaTeX, 2 EPS figures, based on the talk presented by A.V. Kuznetsov at the XVI International Seminar Quarks'2010, Kolomna, Moscow Region, June 6-12, 2010, to appear in the Proceeding

Large magnetic dipole moments for neutrinos with arbitrary masses

We show that there is a general sort of models in which it is possible to have large magnetic dipole moments for neutrinos while keeping their masses arbitrarily small. Some examples of these models are considered.Comment: REVTEX, 8 pages, 2 .eps figure

Chiral Corrections to Lattice Calculations of Charge Radii

Logarithmic divergences in pion and proton charge radii associated with chiral loops are investigated to assess systematic uncertainties in current lattice determinations of charge radii. The chiral corrections offer a possible solution to the long standing problem of why present lattice calculations yield proton and pion radii which are similar in size.Comment: PostScript file only. Ten pages. Figures included. U. of MD Preprint #92-19

Three-Body approach to the K^- d Scattering Length in Particle Basis

We report on the first calculation of the scattering length A_{K^-d} based on a relativistic three-body approach where the two-body input amplitudes coupled to the Kbar N channels have been obtained with the chiral SU(3) constraint, but with isospin symmetry breaking effects taken into account. Results are compared with a recent calculation applying a similar set of two-body amplitudes,based on the fixed center approximation, considered as a good approximation for a loosely bound target, and for which we find significant deviations from the exact three-body results. Effects of the hyperon-nucleon interaction, and deuteron $D$-wave component are also evaluated.Comment: 5 pages, Submitted to Phys. Rev.

Chiral extrapolation of lattice moments of proton quark distributions

We present the resolution of a long-standing discrepancy between the moments of parton distributions calculated from lattice QCD and their experimental values. We propose a simple extrapolation formula for the moments of the nonsinglet quark distribution u-d, as a function of quark mass, which embodies the general constraints imposed by the chiral symmetry of QCD. The inclusion of the leading nonanalytic behavior leads to an excellent description of both the lattice data and the experimental values of the moments.Comment: 9 pages, 1 figure, to appear in Physical Review Letter

Simple supersymmetric solution to the strong CP problem

It is shown that the minimal supersymmetric left-right model can provide a natural solution to the strong {\it CP} problem without the need for an axion, nor any additional symmetries beyond supersymmetry and parity.Comment: Plain Latex. 10 pages, including two figures which are part of the Latex file. Shortened version, to appear in Phys. Rev. Lett. 7