Physical Sciences and Mathematics Commons^™

Random Elastic Networks, Anthony Day, M. Thorpe, W. Xia

Anthony Roy Day

Proceedings of the International Workshop on Condensed Matter Theories, 1988.

Constraints On Left-Right-Symmetric Models From Neutron Decay, As Carnoy, J Deutsch, Br Holstein

Barry R Holstein

The implications for left-right-symmetric models of recent neutron-β-decay asymmetry and lifetime measurements are analyzed. The significance of forthcoming high-precision lifetime measurements is stressed.

Gauge-Invariance And Quantization, Br Holstein

Barry R Holstein

Quantizing theories such as quantum electrodynamics that contain a gauge invariance are discussed via a simple pedagogical example. Canonical and path integral quantization methods are compared.

Semiclassical Treatment Of The Double Well, Br Holstein

Barry R Holstein

The double well potential V(x)= 1/4 λ(x2-α2)2 is addressed using both semiclassical path integral and instanton techniques. The basic physics of the two-state system is shown to arise, and energy levels calculated via the two methods are compared.

Cp Violation In K-]3-Pi, Jf Donoghue, Br Holstein, G Valencia

Barry R Holstein

No abstract provided.

Kobayashi-Maskawa Angles And Su(3) Breaking In Hyperon Beta-Decay, Jf Donoghue, Br Holstein, Sw Klimt

Barry R Holstein

The determination of the Kobayashi-Maskawa matrix element Vus from hyperon β decays has long had a hidden uncertainty due to the almost universal assumption of SU(3) invariance in Cabibbo-type fits, especially since the data definitely indicate the presence of SU(3) breaking. We have reanalyzed the hyperon-decay data using the pattern of symmetry breaking predicted by the quark model including the center-of-mass correction. We find that the SU(3)-broken picture is far superior to the assumption of perfect SU(3), and provides a good fit to experiment. The sensitivity of Vus to the breaking is not large and we find Vus=0.220+/-0.001+/-0.003 (the errors …

Weak Decays Of The H-Dibaryon, Jf Donoghue, E Golowich, Br Holstein

Barry R Holstein

We calculate decay rates and branching fractions for the postulated S=-2 H dibaryon, both for the expected ΔS=1 channels (nΛ,nΣ0,pΣ-) and for the possible ΔS=2 mode (nn). For ΔS=1 decays we find the S waves are dominated by ΔI=(3/2) transitions due to the Pauli principle, which forces the six-quark final state to be in a SU(3) 27-plet. If observed, this would be the first breakdown of the ΔI=1/2 rule. The lifetime is long, of order 10-8 sec, which should be considered in planning experiments. In the ΔS=2 case, we add a consideration of dispersive effects to our previous calculation of …

Gravitational Coupling At Finite Temperature, Jf Donoghue, Br Holstein, Rw Robinett

Barry R Holstein

We discuss a thermodynamic identity which helps explain why ≠ at finite temperature. In addition we complete the discussion of the gravitational force by including the gravitational variation of the temperature. Gradients in the temperature induce extra forces not accounted for by the usual coupling to the energy-momentum tensor.

G. N. Lewis' Atom And Quantum Monte Carlo Studies Of Liquids, Randall W. Hall, Peter G. Wolynes

Randall W. Hall

Chiral Symmetry, Nonleptonic Hyperon Decay, And The Feinberg-Kabir-Weinberg Theorem, Jf Donoghue, Br Holstein

Barry R Holstein

We demonstrate that additional (kaon-pole) diagrams must be appended to the traditional commutator-plus-baryon-pole approach to nonleptonic hyperon decay. The modified analysis satisfied the constraints of the Feinberg-Kabir-Weinberg theorem. The new terms are not numerically significant in the case of the usual current-current Hamiltonian, in the continuum limit, but can be important for work using lattice techniques or for other Hamiltonians.

Electromagnetic And Isopin Breaking Effects Decrease Epsilon'/Epsilon, Jf Donoghue, E Golowich, Br Holstein, J Trampetic

Barry R Holstein

No abstract provided.

Chiral Perturbation-Theory Corrections To Kl-]-Gamma-Gamma, Jf Donoghue, Br Holstein, Ycr Lin

Barry R Holstein

No abstract provided.

Quantum Electrodynamics At Finite Temperature, Jf Donoghue, Br Holstein, Rw Robinett

Barry R Holstein

We present a systematic examination of finite temperature effects in quantum electrodynamics at one loop order. We calculate mass, charge, and wavefunction renormalization, demonstrate the running of the coupling constant at high temperatures, and study the renormalized vertex function and the energy momentum tensor. The confusion in the literature concerning the finite temperature corrections to the electron's magnetic moment is resolved. We also present the finite temperature effects in scalar electrodynamics. Throughout we stress the need to provide a well-defined method to observe a given quantity when interpreting the results of a calculation, and we suggest new techniques which incorporate …

Reanalysis Of Higgs-Boson-Exchange Models Of Cp Violation, Jf Donoghue, Br Holstein

Barry R Holstein

We reexamine the value of ɛ'/ɛ in models where CP violation is due to the exchange of charged Higgs bosons. Previous work has been flawed by incorrect treatment of the chiral properties of weak amplitudes. We use the effective-chiral-Lagrangian framework to clear up these aspects. The resultant value of ɛ'/ɛ is estimated to be in the neighborhood of ɛ'/ɛ=-0.006, although this estimate could be off by a factor of two or three in either direction. This value is consistent with the present experimental bounds.

Behavior Of An Electron In Helium Gas, John Bartholomew, Randall W. Hall, Bruce J. Berne

Randall W. Hall

Gravitational Twins Revisited, Br Holstein

Barry R Holstein

No abstract provided.

Possible Weak Interaction Experiments With Polarized He-3, Br Holstein

Barry R Holstein

No abstract provided.

Forced Harmonic-Oscillator - A Path Integral Approach, Br Holstein

Barry R Holstein

The problem of the harmonic oscillator driven by an external force is explored using path integral techniques. The qualitative features of the solution are demonstrated.

Semileptonic Hyperon Decay - A Problem For Chiral Perturbation-Theory, Jf Donoghue, Br Holstein

Barry R Holstein

We study the recently computed mk2lnm2k corrections to hyperton beta decay found in chiral perturbation theory. The inclusion of these effects is not compatible with the high precision hyperon data, yielding a fit much inferior to the standard assumption of SU(3) invariance. This incompatibility of data and theory is a problem for the application of chiral perturbation theory.

Viscosity Measurements In Dilute Helium-3-Helium-4 Mixtures, George Schmiedeshoff

George Schmiedeshoff

We have measured the viscosity of a dilute mixture of 3He in 4He at temperatures from 5 to 100 mK and in magnetic fields of 0.35, 2.01 and 8.76 T using a vibrating wire viscometer. Subject to our choice of calibration function, the data at 0.35 T is in good agreement with theory. Due to an interaction of our viscometer with the magnetic field the motion of the wire at 2.01 and 8.76 T is not understood; however, the 2.01 T data can be brought into agreement with the 0.35 T data by adjusting a geometrical constant. An increase in …

Renormalization Of The Energy-Momentum Tensor And The Validity Of The Equivalence Principle At Finite Temperature, Jf Donoghue, Br Holstein, Rw Robinett

Barry R Holstein

Using the techniques of finite-temperature field theory we renormalize the electromagnetic and gravitational couplings of an electron which is immersed in a heat bath with T

Possibilities For Finite Grand Unification With N = 2 Supersymmetry, Asim Gangopadhyaya

Asim Gangopadhyaya

Predicting The Proton Mass From Pi-Pi-Scattering Data, Jf Donoghue, E Golowich, Br Holstein

Barry R Holstein

We relate experimental information on ππ scattering to tree-level effective chiral Lagrangians. The result is of a form similar to that used in Skyrme-type models of the proton, where the nucleons are described as topologically stable solitons of the chiral fields. In such models, one can express the proton mass in terms of measured scattering data, with the result Mp=880±300 MeV. We interpret this as a consistency test for the Skyrme models.

Renormalization And Radiative-Corrections At Finite Temperature, Jf Donoghue, Br Holstein

Barry R Holstein

We discuss the renormalization prescription for fermions at finite temperature and describe the procedure for calculating radiative corrections. Novel features arise, such as a lack of explicit Lorentz invariance, 1k2 singularities, and the absorption of soft photons from the background heat bath. The methods are illustrated by explicit calculation of the electron renormalization and the radiative corrections to H-->e+e- (with H being spin zero) in finite-temperature QED.

Bound-States, Virtual States, And Non-Exponential Decay Via Path-Integrals, Br Holstein

Barry R Holstein

Using path integral techniques we demonstrate how three quantum-mechanical phenomena-alpha decay, nonexponential decay, and resonant scattering-can be treated. This procedure is an algebraic one yet reproduces the usual results obtained via solution of the Schrödinger equation via WKB methods.

Y Expansion For Directed Lattice Animals, Anthony Day, T. Lubensky

Anthony Roy Day

No abstract provided.

Path-Integrals And The Wkb Approximation, Br Holstein, Ar Swift

Barry R Holstein

The WKB approximation is demonstrated to be formally identical to the semiclassical limit of the Feynman path integral propagator. In the limit that the path integral propagator is dominated by the classical particle trajectory, it is identical to the propagator calculated directly from WKB wave functions in the stationary phase approximation.

Comment On Particle Mixing And Delta-I= 3/2 Terms In Non-Leptonic Weak Decays, Br Holstein

Barry R Holstein

A recent paper by Gusbin concludes that ΔI=3/2 terms in K→πη can substantially modify particle-mixing contributions to K+→π+π0. Using techniques which can successfully reproduce the experimental features of the K→ππ decays, we argue that this seems unlikely.

Implications Of Nuclear Parity Non-Conservation, Jf Donoghue, Br Holstein

Barry R Holstein

From recent developments in the area of nuclear parity nonconservation we extract evidence for (1) SU(3) /soft-pion breaking in weak pionic vertices, and (2) larger values of quark masses than have been used in previous evaluations of "penguin" matrix elements.

Induced Tensor And Ft Asymmetries, Br Holstein

Barry R Holstein

Looked at from a model-independent point of view, the existence of a non-zero first class induced tensor form factor appears to provide a substantial contribution to the observed ft asymmetry in mirror Gamow-Teller beta decays. However, we demonstrate that, when analyzed in terms of the impulse approximation, this is only a negligibly small effect. RADIOACTIVITY Calculated contribution to ft asymmetry from first class induced tensor.