Dallas C. Kennedy

Electroweak radiative corrections with an effective lagrangian: Four-fermions processes

We present a new, more concise method for computing and organizing electroweak radiative corrections, based on an effective lagrangian and incorporating a large class of diagrams into a few simple running couplings without use of truncated renormalization group approximations. We apply this technique to the case of four-fermion processes. Special emphasis is placed on the effects of heavy particles on low-energy physics and how such phenomena can be classified and measured in the new generation of precision electroweak experiments - in particular, experiments with polarized e− beams at the SLC and LEP.

Implications of combined solar neutrino observations and their theoretical uncertainties

Constraints on the core temperature ([ital T][sub [ital c]]) of the Sun and on neutrino-oscillation parameters are obtained from the existing solar neutrino data, including the recent GALLEX, SAGE, and Kamiokande III results. (1) A purely astrophysical solution to the solar-neutrino problem is strongly disfavored by the data: the Homestake and Kamiokande data together are incompatible with any temperature in the Sun; the central values of both the SAGE and GALLEX results require a large reduction of [ital T][sub [ital c]] when they are fit to a cooler Sun. (2) Assuming the standard solar model (SSM) and matter-enhanced neutrino oscillations, the Mikheyev-Smirnov-Wolfenstein (MSW) parameters are constrained to two small regions: nonadiabatic oscillations with [Delta][ital m][sup 2]=(0.3--1.2)[times]10[sup [minus]5] eV[sup 2], sin[sup 2]2[theta]=(0.4--1.5)[times]10[sup [minus]2], or large mixing-angle oscillations with [Delta][ital m][sup 2]=(0.3--3)[times]10[sup [minus]5] eV[sup 2], sin[sup 2]2[theta]=0.6--0.9. The nonadiabatic solution gives a considerably better fit. For [nu][sub [ital e]] oscillations into sterile neutrinos, the allowed region (90% C.L.) is constrained to nonadiabatic oscillations. As long as the SSM is assumed, the neutrino mixing angles are at least four times larger, or considerably smaller, than the corresponding quark mixing angles.

Seesaw model solutions of the solar neutrino problem

Abstract We re-examine solutions to the solar neutrino oscillations, decaying neutrinos and a cooler center of the sun. Comparison of the Homestake and Kamiokande II observations implies that low-energy neutrinos are more suppressed than high-energy, disfavoring the large-mass adiabatic MSW resonance and allowing us to exclude non-standard solar models with a simple reduction of core temperature. Diagonal ( sin 2 2θ - 0.004−0.5, Δm 2 ⋍ 0.08−10 meV 2 ) , vertical large-angle ( sin 2 ⋍ 0.6−0.9, Δm 2 ⋍ 0.08−2, 4−60 meV 2 ) , and part of the horizontal ( sin 2 2θ ⋍ 0.02−0.6, Δm 2 ⋍ 80 meV 2 ) MSW solutions are compatible with these data (meV = 10−3 eV). The present SAGE results disfavor non-standard solar models and the horizontal MSW solution. Assuming νe → νμ conversion, we show that seesaw models of neutrino masses imply mνμ = 0.3−9 meV, intermediate-scale symmetry breaking O(109–1012) GeV, and a τ-neutrino mass with cosmological ramifications in some cases and laboratory or atmospheric νμ − ντ oscillations. While seesaw predictions for neutrino masses are model-dependent and subject to large uncertainties, we prove that leptonic mixing angles are similar to quark mixings for a wide range of models. We also present two specific seesaw models compatible with electroweak neutral current and proton decay constraints, including radiative corrections to the seesaw predictions.

Non-abelian Q-stars

Abstract We construct a new class of non-topological soliton stars which appears in global non-abelian field theories coupled to classical Einstein gravity. It is the analogue of the Q-stars recently found in abelian theories. If μ (of order 10 − to 10 4 GeV) is a free-particle inverse Compton wavelength and m Pl is the Planck mass, these objects have energy densities e ∼ μ 4 , radii r ∼ m Pl / μ 2 , global charges q ∼ m Pl 3 / μ 3 , and masses M ∼ m Pl 3 / μ 2 obeying a generalized Chandrasekhar limit. We give an explicit SO(3) example which demonstrates their very simple structure: the stellar surface reproduces the non-abelian Q-ball, but within the star the fields are no longer constant.

How hot is radiation

A self-consistent approach to defining nonequilibrium radiation temperature is discussed using the distribution of the energy over microstates. We begin rigorously with ensembles of Hilbert spaces and end with practical examples based mainly on the far from equilibrium radiation of lasers. We show that very high, but not infinite, laser radiation temperatures depend on intensity and frequency. Heuristic definitions of temperature derived from a misapplication of equilibrium arguments are shown to be incorrect. More general conditions for the validity of nonequilibrium temperatures also are established.

Variational principles for stellar structure

The four equations of stellar structure are reformulated as two alternate pairs of variational principles. Different thermodynamic representations lead to the same hydromechanical equations, but the thermal equations require, not the entropy, but the temperature as the thermal field variable. Our treatment emphasizes the hydrostatic energy and the entropy production rate of luminosity produced and transported. The conceptual and calculational advantages of integral over differential formulations of stellar structure are discussed along with the difficulties in describing stellar chemical evolution by variational principles.

A New Limit on the Antiproton Lifetime

Measurements of the cosmic-ray /p ratio are compared with predictions from an inhomogeneous disk-diffusion model of production and propagation within the Galaxy, combined with a calculation of the modulation of the interstellar cosmic-ray spectra as the particles propagate through the heliosphere to the Earth. The predictions agree with the observed /p spectrum. Adding a finite lifetime to the model, we obtain the limit τ > 0.8 Myr (90% CL).

Analytic Models for the Mechanical Structure of the Solar Core

All stars exhibit universal central behavior in terms of new homology variables (u,w). In terms of these variables, we obtain simple analytic fits to numerical standard solar models for the core and radiative zones of the zero-age main-sequence and present Suns with a few global parameters. With these analytic fits, different theoretical models of the solar core, neutrino fluxes, and helioseismic observations can be parametrized and compared.

Minimum entropy production of neutrino radiation in the steady state

A thermodynamic minimum principle valid for photon radiation is shown to hold for arbitrary geometries. It is successfully extended to neutrinos, in the zero mass and chemical potential case, following a parallel development of photon and neutrino statistics. This minimum principle stems more from that of Planck than that of classical Onsager–Prigogine irreversible thermodynamics. Its extension from bosons to fermions suggests that it may have a still wider validity.

Invariant relationships deriving from classical scaling transformations

Because scaling symmetries of the Euler–Lagrange equations are generally not variational symmetries of the action, they do not lead to conservation laws. Instead, an extension of Noethers theorem reduces the equations of motion to evolutionary laws that prove useful, even if the transformations are not symmetries of the equations of motion. In the case of scaling, symmetry leads to a scaling evolutionary law, a first-order equation in terms of scale invariants, linearly relating kinematic and dynamic degrees of freedom. This scaling evolutionary law appears in dynamical and in static systems. Applied to dynamical central-force systems, the scaling evolutionary equation leads to generalized virial laws, which linearly connect the kinetic and potential energies. Applied to barotropic hydrostatic spheres, the scaling evolutionary equation linearly connects the gravitational and internal energy densities. This implies well-known properties of polytropes, describing degenerate stars and chemically homogeneous...