Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 31 - 60 of 83
Full-Text Articles in Physical Sciences and Mathematics
Wavefunction Renormalization And Nuclear Parity Nonconservation, Jf Donoghue, Br Holstein
Wavefunction Renormalization And Nuclear Parity Nonconservation, Jf Donoghue, Br Holstein
Barry R Holstein
It is argued that a recent calculation, which envisions a major role for a parity violating wave function renormalization term, predicts effects in a variety of low energy weak processes which are in contradiction to experiment. It is also shown that the physics of such renormalization terms are already included in previous work.
Long Distance Effects And Strangeness In The Nucleon, John Donoghue, Barry Holstein, Tobias Huber, Andreas Ross
Long Distance Effects And Strangeness In The Nucleon, John Donoghue, Barry Holstein, Tobias Huber, Andreas Ross
Barry R Holstein
We discuss the calculation of the strange magnetic radius of the proton in chiral perturbation theory. In particular, we investigate the low-energy component of the loop integrals involving kaons. We separate the chiral calculation into a low-energy part and a high-energy component through use of a momentum space separation scale. This separation shows that most of the chiral calculation comes from high energies where the effective field theory treatment is not valid. The resulting low-energy prediction is in better agreement with dispersive treatments. Finally, we briefly discuss magnetic moments and show how our techniques can help resolve an old puzzle …
Blue Skies And Effective Interactions, Br Holstein
Blue Skies And Effective Interactions, Br Holstein
Barry R Holstein
This paper shows how the basic physics of Rayleigh scattering, responsible for the blueness of the sky, can be extracted using the techniques of effective interactions, which have become widespread in contemporary particle and nuclear physics.
Measurement Of The Weak Neutral Current Via Nuclear Parity Violation, Jf Donoghue, Br Holstein
Measurement Of The Weak Neutral Current Via Nuclear Parity Violation, Jf Donoghue, Br Holstein
Barry R Holstein
Present low-energy experiments which detect parity violation in nuclei are analyzed, and a consistent set of weak couplings is extracted. Using symmetries and the quark model, it is shown that a parity-violating weak-neutral-current contribution is required by the data, and we extract values sin2θW=0.0±0.4 or ρ=1.1±0.2, consistent with other determinations. The error quoted is statistical only, and does not include a possibly sizable theoretical uncertainty. On the other hand, if we assume the world-average values for ρ and θW, we can obtain from the data (with minimal quark-model assumptions) the matrix element of an operator which is closely related to …
Semiclassical Treatment Of Above-Barrier Scattering, Br Holstein
Semiclassical Treatment Of Above-Barrier Scattering, Br Holstein
Barry R Holstein
We show how the semiclassical approach to barrier penetration based on path integral methods may be generalized to handle the case that the energy of the scattered particle is greater than the height of the potential barrier.
Analysis Of Delta-S=1 Non-Leptonic Weak Decays And The Delta-I=1-2 Rule, Jf Donoghue, Eugene Golowich, Wa Ponce, Br Holstein
Analysis Of Delta-S=1 Non-Leptonic Weak Decays And The Delta-I=1-2 Rule, Jf Donoghue, Eugene Golowich, Wa Ponce, Br Holstein
Barry R Holstein
Current-algebra and quark-model methods are used to investigate hyperon and kaon transition amplitudes for various contributions to the weak nonleptonic Hamiltonian of the Weinberg-Salam model. Substantial enhancements are found for matrix elements of certain operators which are induced by quantum-chromodynamic radiative corrections and contain right-handed currents. These operators improve the agreement with experiment in most cases, although problems remain in P-wave hyperon amplitudes. In this approach, the ΔI=1/2 rule is understandable in both kaons and baryons under plausible assumptions.
Isospin Mixing And Model Dependence, Es Na, Br Holstein
Isospin Mixing And Model Dependence, Es Na, Br Holstein
Barry R Holstein
We show that recent calculations of ΔI=3/2 effects in nonleptonic hyperon decay induced by md-mu≠0 are subject to significant model dependence. [S0556-2821(97)04819-4]
Anomalies In Quantum Mechanics: The 1/R(2) Potential, Sa Coon, Br Holstein
Anomalies In Quantum Mechanics: The 1/R(2) Potential, Sa Coon, Br Holstein
Barry R Holstein
An anomaly is said to occur when a symmetry that is valid classically becomes broken as a result of quantization. Although most manifestations of this phenomenon are in the context of quantum field theory, there are at least two cases in quantum mechanics—the two-dimensional delta function interaction and the 1/r2 potential. The former has been treated in this journal; in this article we discuss the physics of the latter together with experimental consequences.
Higher Order Polarizabilities Of The Proton, Br Holstein, D Drechsel, B Pasquini, M Vanderhaeghen
Higher Order Polarizabilities Of The Proton, Br Holstein, D Drechsel, B Pasquini, M Vanderhaeghen
Barry R Holstein
Compton scattering results are used to probe proton structure via measurement of higher order polarizabilities. Values for αE2p, βE2p, αEνp, and βEνp determined via dispersion relations are compared to predictions based upon chiral symmetry and from the constituent quark model. Extensions to spin polarizabilities are also discussed.
Quark-Model Calculation Of The Weak Electric Coupling In Semi-Leptonic Baryon Decay, Jf Donoghue, Br Holstein
Quark-Model Calculation Of The Weak Electric Coupling In Semi-Leptonic Baryon Decay, Jf Donoghue, Br Holstein
Barry R Holstein
The weak electric form factor g2 is calculated in the nonrelativistic quark model (NRQM) and the MIT bag model for weak ΔS=1 semileptonic transitions. The bag-model result is g2/g1=0.30 with the NRQM result roughly twice this. Other weak transition form factors are tabulated, including expected SU(3)-breaking effects.
Future-Directions In Cp-Violation, Br Holstein
Future-Directions In Cp-Violation, Br Holstein
Barry R Holstein
Ongoing experiments seeking CP violating effects in the neuron dipole moment and in ε1/ε are at the stage where they will yield critical constraints on attempts to pinpoint the origin of this phenomenon. A number of additional experiments which appear promising in this regard are proposed.
An -> Nn Weak Interaction In Effective-Field Theory, A Parreno, C Bennhold, Br Holstein
An -> Nn Weak Interaction In Effective-Field Theory, A Parreno, C Bennhold, Br Holstein
Barry R Holstein
The nonleptonic weak ∣ΔS∣=1 ΛN interaction, responsible for the dominant nonmesonic decay of all but the lightest hypernuclei, is studied in the framework of an effective-field theory. The long-range physics is described through tree-level exchange of the SU(3) Goldstone bosons, while the short-range potential is parametrized in terms of the lowest-order contact terms. We obtain reasonable fits to available weak hypernuclear decay rates and quote the values for the parity-violating asymmetry as predicted by the present effective-field theory.
The Extended Galilean Transformation And The Path Integral, Br Holstein
The Extended Galilean Transformation And The Path Integral, Br Holstein
Barry R Holstein
We demonstrate how the behavior of the Schrödinger equation under the transformation, x′=x+ξ(t), t′=t, can be easily discerned within the path integral formalism.
Delta Contributions To The Parity-Violating Nuclear-Interaction, Gb Feldman, Ga Crawford, J Dubach, Br Holstein
Delta Contributions To The Parity-Violating Nuclear-Interaction, Gb Feldman, Ga Crawford, J Dubach, Br Holstein
Barry R Holstein
A quark-model picture which incorporates SU(6)w symmetry is utilized to calculate the weak Δ-nucleon-meson and Δ-Δ-meson parity-violating vertices for π, ρ, and ω mesons, thus extending previous work in the nucleon sector. The effective quark Hamiltonian is based upon the renormalization-group-corrected Weinberg-Salam model. The calculated parity-violating vertices are used to determine the coupling constants in an effective baryon Hamiltonian. We give ‘‘best’’ values as well as estimates of the ranges of uncertainty.
Strong Field Pair Production, Br Holstein
Strong Field Pair Production, Br Holstein
Barry R Holstein
The subject of strong field pair creation, which has important cosmological implications associated with black hole decay, is studied in the simpler context of strong electric fields. The pair creation rate is calculated by formal methods first given by Schwinger as well as via less forbidding wave function techniques.
Weak Nucleon Nucleon Meson Couplings And Nuclear Parity Violation, Br Holstein
Weak Nucleon Nucleon Meson Couplings And Nuclear Parity Violation, Br Holstein
Barry R Holstein
After many years of careful theoretical and experimental study of nuclear parity violation, rough empirical values for weak parity violating nucleon–nucleon–meson vertices have been deduced. We address some of the physics which has been learned from this effort and show that it has implications for work going on outside this field.
Variations On The Aharonov-Bohm Effect, Br Holstein
Variations On The Aharonov-Bohm Effect, Br Holstein
Barry R Holstein
Three variations of the usual two‐slit electron diffraction experiment—insertion of a solenoid, of a rotating superconductor, and of an electric line charge in a neutron diffraction experiment—are examined. Each is shown to lead to a shift in the interference pattern.
Weak And Electromagnetic Interactions Of Hyperons: A Chiral Approach, Br Holstein
Weak And Electromagnetic Interactions Of Hyperons: A Chiral Approach, Br Holstein
Barry R Holstein
A range of issues in the field of weak and electromagnetic interactions of hyperons is presented from the perspective of (broken) chiral symmetry, together with an assessment of where important challenges remain.
Effective Interactions And The Hydrogen Atom, Br Holstein
Effective Interactions And The Hydrogen Atom, Br Holstein
Barry R Holstein
The technique of effective interactions, which has become commonplace in contemporary particle/nuclear physics, is used to analyze the structure of hydrogen atom energy levels.
Non-Leptonic Hyperon Decays In Chiral Perturbation Theory, B Borasoy, Br Holstein
Non-Leptonic Hyperon Decays In Chiral Perturbation Theory, B Borasoy, Br Holstein
Barry R Holstein
The non-leptonic hyperon decays are analyzed up to one-loop order including all counterterms in the framework of heavy baryon chiral perturbation theory. We use the exchange of the spin- decuplet resonances as an indication of which low-energy constants contribute significantly to these investigated processes. We choose four independent decay amplitudes that are not related by isospin relations in order to perform a fit for the pertinent low-energy constants and find a satisfactory fit both for s- and p-waves. The chiral corrections to the lowest order forms for the s-waves are moderate whereas there are significant modifications of the p-wave amplitudes.
Diagonalization Of The Dirac Equation: An Alternative Approach, Br Holstein
Diagonalization Of The Dirac Equation: An Alternative Approach, Br Holstein
Barry R Holstein
The reduction of a relativistic Hamiltonian to its effective nonrelativistic form, usually accomplished via a Foldy–Wouthuysen transformation, is derived via Lagrangian methods. This technique provides a pedagogically interesting introduction to the so-called heavy baryon field theory.
Barrier Penetration Via Path-Integrals, Br Holstein, Ar Swift
Barrier Penetration Via Path-Integrals, Br Holstein, Ar Swift
Barry R Holstein
Path integral methods are applied to the problem of barrier penetration. By an excursion into complex time it is shown how the ideal of a ’’classical’’ path may be generalized to give a simple geometrical derivation of the usual WKB formulas.
Nuclear Parity-Violation Parameter H-Rho(1)', Br Holstein
Nuclear Parity-Violation Parameter H-Rho(1)', Br Holstein
Barry R Holstein
Previous theoretical work has been unable to predict a reliable value for the nuclear parity-violation parameter hρ(1)′. Using a 1/2- pole model we estimate the size of this term and demonstrate that it is very unlikely to have a significant effect on theoretical calculations.
Effective Lagrangians And Quantum-Mechanics - The Index Of Refraction, Br Holstein
Effective Lagrangians And Quantum-Mechanics - The Index Of Refraction, Br Holstein
Barry R Holstein
Using path integral quantization of a harmonic oscillator–electric field system, it is demonstrated how the familiar expression for the index of refraction of a gas can be obtained by use of the so‐called effective Lagrangian.
Answer To Question #4. Is There A Physics Application That Is Best Analyzed In Terms Of Continued Fractions?, Br Holstein
Answer To Question #4. Is There A Physics Application That Is Best Analyzed In Terms Of Continued Fractions?, Br Holstein
Barry R Holstein
No abstract provided.
Direct Quark-Model Calculation Of Weak Nonleptonic Matrix-Elements, Jf Donoghue, Br Holstein
Direct Quark-Model Calculation Of Weak Nonleptonic Matrix-Elements, Jf Donoghue, Br Holstein
Barry R Holstein
It is shown how wave-packet techniques developed by Donoghue and Johnson may be utilized to calculate parity-violating nonleptonic hyperon decay amplitudes directly—without the use of current algebra and PCAC (partial conservation of axial-vector current).
The Principle Of Equivalence At Finite Temperature, Jf Donoghue, Br Holstein, Rw Robinett
The Principle Of Equivalence At Finite Temperature, Jf Donoghue, Br Holstein, Rw Robinett
Barry R Holstein
We demonstrate that the equivalence principle is violated by radiative corrections to the gravitational and inertial masses at finite temperature. We argue that this result can be attributed to the Lorentz noninvariance of the finite temperature vacuum.
The Van Der Waals Interaction, Br Holstein
The Van Der Waals Interaction, Br Holstein
Barry R Holstein
The interaction between two neutral but polarizable systems at separation R, usually called the van der Waals force, is discussed from different points of view. The change in character from 1/R6 to 1/R7 due to retardation is explained.
Quantum-Mechanics In Momentum-Space - The Coulomb System, Br Holstein
Quantum-Mechanics In Momentum-Space - The Coulomb System, Br Holstein
Barry R Holstein
We examine the Coulomb system in momentum space. Both by directly summing the multiple scattering series as well as by use of symmetry techniques we demonstrate how the familiar results for scattering amplitude and bound state wave functions/energy levels can be derived.
Kaon Decays And A Determination Of The Scale Of Chiral Symmetry, Jf Donoghue, Eugene Golowich, Br Holstein
Kaon Decays And A Determination Of The Scale Of Chiral Symmetry, Jf Donoghue, Eugene Golowich, Br Holstein
Barry R Holstein
Using effective chiral Lagrangians, we consider the occurrence of quadratic terms in the ΔI=1/2 K→3π matrix element. The inclusion of higher-derivative Lagrangians leads to a significant improvement over the usual current-algebra analysis. This allows an extraction directly from experimental data of Λχ, a measure of the scale of chiral symmetry. We give an operational definition of the chiral scale, and find Λχ≈1 GeV. The issue of uncertainty in the phenomenological determination of the B parameter is clarified.