Physical Sciences and Mathematics | Open Access Articles

Effective Field Theory In Nuclear Physics, Martin J. Savage, Br Holstein

Barry R Holstein

The Electromagnetic and Hadronic Physics sub-community of nuclear physics held a town hall meeting at Jefferson Lab during November 30 to December 4 of 2000. This is is our combined contribution to the white paper that will result from this meeting.

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Higgs-Boson-Exchange Models Of Cp Violation And K-]2pi, Jf Donoghue, Js Hagelin, Br Holstein

Barry R Holstein

Work by Deshpande and Sanda, which appears to invalidate Higgs-boson-exchange models of CP noninvariance, is buttressed by (i) use of the MIT bag model to calculate matrix elements, (ii) use of experimental rather than calculated numbers for the K→2π decay amplitude and the KL-KS mass difference, and (iii) inclusion of possible t-quark effects. We conclude that, barring accidental cancellations, such Higgs-boson-exchange models are incompatible with experiment.

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Resonances In Weak Nonleptonic Omega(-) Decay, B Borasoy, Br Holstein

Barry R Holstein

We examine the importance of JP=1/2+,1/2- resonances for weak nonleptonic Ω- decays within the framework of chiral perturbation theory. The spin-1/2 resonances are included into an effective theory and the tree contributions to the Ω- decays are calculated. We find significant contributions to the decay amplitudes and satisfactory agreement with experiment. This confirms and extends previous results wherein such spin-1/2 resonances were included in nonleptonic and radiative-nonleptonic hyperon decays.

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Evidence For Su(3) Breaking In Cabibbo-Type Fits Of Semi-Leptonic Hyperon Decay, Jf Donoghue, Br Holstein

Barry R Holstein

We analyze recent precision experiments involving semileptonic hyperon decay and demonstrate that there exists definite evidence for SU(3) breaking. The type of breaking observed is a difference in the D/(F+D) ratios in the ΔS=0 and ΔS=1 sectors, which is at variance with the simplest quark-model expectations. We comment on the relevance of symmetry breaking to the determination of weak mixing angles.

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Electromagnetic Self-Energies Of Pseudoscalar Mesons And Dashen Theorem, Jf Donoghue, Br Holstein, D Wyler

Barry R Holstein

The calculation of the electromagnetic mass shifts of π, K mesons is studied using a model incorporating chiral symmetry and vector dominance. Significant SU(3) breaking to Dashen's theorem is found, allowing a resolution of the long-standing discrepancy between the quark-mass ratio (md-mu)/ms found from η→3π decay and that from the K+-K0 mass difference.

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Photon-Photon Scattering, Pion Polarizability, And Chiral-Symmetry, Jf Donoghue, Br Holstein

Barry R Holstein

Recent attempts to detect the pion polarizability via analysis of γγ→ππ measurements are examined. The connection between calculations based on dispersion relations and on chiral perturbation theory is established by matching the low-energy chiral amplitude with that given by a full dispersive treatment. Using the values for the polarizability required by chiral symmetry, predicted and experimental cross sections are shown to be in agreement.

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Generalized Polarizabilities And The Chiral Structure Of The Nucleon, Tr Hemmert, Br Holstein, G Knochlein, S Scherer

Barry R Holstein

We discuss the virtual Compton scattering reaction e−p → e−pγ at low energies. We present results for the generalized polarizabilities of the nucleon obtained in heavy baryon chiral perturbation theory at O(p3).

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Effective Field Theory And Xpt, Br Holstein

Barry R Holstein

A brief introduction to the subject of chiral perturbation theory ($\chi$pt) is given, including a discussion of effective field theory and application to the upcoming Bates virtual Compton scattering measurement.

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Chiral Loops In Pi-0,Eta-0-]Gamma-Gamma And Eta-Eta' Mixing, Jf Donoghue, Br Holstein, Ycr Lin

Barry R Holstein

We compute the one-loop corrections to the Wess-Zumino Lagrangean governing π0, η8→γγ. The SU(3) relation between the two decay rates receives modifications of order mK2lnmK2, as does the Gell-Mann-Okubo mass formula. A consistent picture of η-η′ mixing emerges from both the two-photon widths and the mass matrix, however with a mixing angle θ≈-20° instead of the usual θ≈-10°.

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Dispersive Effects In D0-Dbaro Mixing, Jf Donoghue, Eugene Golowich, Br Holstein, J Trampetic

Barry R Holstein

We estimate the size of dispersive effects in ΔC=2 interactions and find that they represent in fact the dominant components of D0-D¯0 mixing. The box diagram is suppressed by several orders of magnitude due to the small values of light-quark masses. Crucial to this argument is a discussion of how the Glashow-Iliopoulos-Maiani mechanism works in the dispersive sector.

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Subnuclear Structure - Nucleons Just Yield To Pressure, Br Holstein

Barry R Holstein

No abstract provided.

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Light Baryon Magnetic Moments And N ->Delta Gamma Transition In A Lorentz Covariant Chiral Quark Approach, A Faessler, T Gutsche, Br Holstein, Ve Lyubovitskij, D Nicmorus, K Pumsa-Ard

Barry R Holstein

We calculate magnetic moments of light baryons and N→Δγ transition characteristics using a manifestly Lorentz covariant chiral quark approach for the study of baryons as bound states of constituent quarks dressed by a cloud of pseudoscalar mesons.

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Nuclear Parity Violation 1984 - An Optimists Perspective, Br Holstein

Barry R Holstein

The present theoretical understanding of nuclear parity nonconservation is assesssed. Using the quark model to calculate weak couplings and empirical values obtained in s-d nuclei we determine sin2thetaw=0.33±0.19. Unfortunately, the error bars here are purely statistical and do not include a substantial ``systematic'' uncertainty associated with the theory.

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Hadronic Parity Violation: Past, Present, And Future, Br Holstein

Barry R Holstein

The history of hadronic parity violation is reviewed, from its beginning in 1957 to the present time. The current state of the subject is shown to be confused and a program to resolve this dilemma, including theoretical calculations using effective theoretic methods together with new low energy experiments in low A systems, is proposed.

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Temperature Measured By A Uniformly Accelerated Observer, Jf Donoghue, Br Holstein

Barry R Holstein

By use of elementary quantum‐mechanical arguments we demonstrate how an observer with uniform acceleration a perceives himself as immersed in a heat bath of temperature kT=aℏ/2πc.

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The Stability Of Hot Curved Space, Ps Gribosky, Jf Donoghue, Br Holstein

Barry R Holstein

The propagator is evaluated for the situation of a non-interacting scalar field at non-zero temperature in curved space-time. The coincidence limit is taken and the corresponding effective Lagrangian is constructed. Fluctuations are determined using a background metric which satisfies the Einstein equations. The resulting energy-momentum tensor is found to be that for an imperfect fluid. Metric fluctuations are found to be unstable (for most values of the cosmological constant) with an exponential growth characterized by a Jeans mass squared which is twice the classical value. Comparisons with previous calculations are also made.

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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.

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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 …

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Heavy Baryon Chiral Perturbation Theory With Light Deltas, Tr Hemmert, Br Holstein, J Kambor

Barry R Holstein

We demonstrate how heavy mass methods, previously applied to chiral perturbation theory calculations involving the interactions of nucleons and pions, can be generalized to include interactions with the (1232) in a systematic formalism which we call the `small-scale expansion'.

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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.

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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 …

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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.

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Nucleon Anapole Moment And Parity-Violating Ep Scattering, Sl Zhu, Sj Puglia, Br Holstein, Mj Ramsey-Musolf

Barry R Holstein

Parity-violating (PV) interactions among quarks in the nucleon induce a PV γNN coupling, or anapole moment (AM). We compute electroweak gauge-independent contributions to the AM through O(1/Λχ2) in chiral perturbation theory. We estimate short-distance PV effects using resonance saturation. The AM contributions to PV electron-proton scattering slightly enhance the axial vector radiative corrections, RAp, over the scale implied by the standard model when weak quark-quark interactions are neglected. We estimate the theoretical uncertainty associated with the AM contributions to RAp to be large, and discuss the implications for the interpretation PV of ep scattering.

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Dispersion-Relations And The Nucleon Polarizability, Br Holstein, Am Nathan

Barry R Holstein

Recent experimental results on the proton and neutron polarizabilities are examined from the point of view of backward dispersion relations. Results are found to be in reasonable agreement with the measured values. A rigorous relationship between the nucleon and pion polarizabilities is derived and shown to be in excellent agreement with several models.

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Compton Scattering And The Spin Structure Of The Nucleon At Low Energies, Tr Hemmert, Br Holstein, J Kambor, G Knochlein

Barry R Holstein

We analyze polarized Compton scattering which provides information on the spin-structure of the nucleon. For scattering processes with photon energies up to 100 MeV the spin-structure dependence can be encoded into four independent parameters—the so-called spin-polarizabilities γi, i=1,…,4, of the nucleon, which we calculate within the framework of the “small scale expansion” in SU(2) baryon chiral perturbation theory. Specific application is made to “forward” and “backward” spin-polarizabilities.

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Introduction To Effective Field Theory, Br Holstein

Barry R Holstein

This review summarizes effective field theory techniques, which are the modern theoretical tools for exploiting the existence of hierarchies of scale in a physical problem. The general theoretical framework is described and evaluated explicitly for a simple model. Power-counting results are illustrated for a few cases of practical interest, and several applications to quantum electrodynamics are described.

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Derivation Of The Weak Quark-Model Interaction Between Nucleons, Br Holstein

Barry R Holstein

No abstract provided.

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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.

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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]

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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.

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Full-Text Articles in Physical Sciences and Mathematics

Effective Field Theory In Nuclear Physics, Martin J. Savage, Br Holstein

Barry R Holstein

Higgs-Boson-Exchange Models Of Cp Violation And K-]2pi, Jf Donoghue, Js Hagelin, Br Holstein

Barry R Holstein

Resonances In Weak Nonleptonic Omega(-) Decay, B Borasoy, Br Holstein

Barry R Holstein

Evidence For Su(3) Breaking In Cabibbo-Type Fits Of Semi-Leptonic Hyperon Decay, Jf Donoghue, Br Holstein

Barry R Holstein

Electromagnetic Self-Energies Of Pseudoscalar Mesons And Dashen Theorem, Jf Donoghue, Br Holstein, D Wyler

Barry R Holstein

Photon-Photon Scattering, Pion Polarizability, And Chiral-Symmetry, Jf Donoghue, Br Holstein

Barry R Holstein

Generalized Polarizabilities And The Chiral Structure Of The Nucleon, Tr Hemmert, Br Holstein, G Knochlein, S Scherer

Barry R Holstein

Effective Field Theory And Xpt, Br Holstein

Barry R Holstein

Chiral Loops In Pi-0,Eta-0-]Gamma-Gamma And Eta-Eta' Mixing, Jf Donoghue, Br Holstein, Ycr Lin

Barry R Holstein

Dispersive Effects In D0-Dbaro Mixing, Jf Donoghue, Eugene Golowich, Br Holstein, J Trampetic

Barry R Holstein

Subnuclear Structure - Nucleons Just Yield To Pressure, Br Holstein

Barry R Holstein

Light Baryon Magnetic Moments And N ->Delta Gamma Transition In A Lorentz Covariant Chiral Quark Approach, A Faessler, T Gutsche, Br Holstein, Ve Lyubovitskij, D Nicmorus, K Pumsa-Ard

Barry R Holstein

Nuclear Parity Violation 1984 - An Optimists Perspective, Br Holstein

Barry R Holstein

Hadronic Parity Violation: Past, Present, And Future, Br Holstein

Barry R Holstein

Temperature Measured By A Uniformly Accelerated Observer, Jf Donoghue, Br Holstein

Barry R Holstein

The Stability Of Hot Curved Space, Ps Gribosky, Jf Donoghue, Br Holstein

Barry R Holstein

Wavefunction Renormalization And Nuclear Parity Nonconservation, Jf Donoghue, Br Holstein

Barry R Holstein

Long Distance Effects And Strangeness In The Nucleon, John Donoghue, Barry Holstein, Tobias Huber, Andreas Ross

Barry R Holstein

Heavy Baryon Chiral Perturbation Theory With Light Deltas, Tr Hemmert, Br Holstein, J Kambor

Barry R Holstein

Blue Skies And Effective Interactions, Br Holstein

Barry R Holstein

Measurement Of The Weak Neutral Current Via Nuclear Parity Violation, Jf Donoghue, Br Holstein

Barry R Holstein

Semiclassical Treatment Of Above-Barrier Scattering, Br Holstein

Barry R Holstein

Nucleon Anapole Moment And Parity-Violating Ep Scattering, Sl Zhu, Sj Puglia, Br Holstein, Mj Ramsey-Musolf

Barry R Holstein

Dispersion-Relations And The Nucleon Polarizability, Br Holstein, Am Nathan

Barry R Holstein

Compton Scattering And The Spin Structure Of The Nucleon At Low Energies, Tr Hemmert, Br Holstein, J Kambor, G Knochlein

Barry R Holstein

Introduction To Effective Field Theory, Br Holstein

Barry R Holstein

Derivation Of The Weak Quark-Model Interaction Between Nucleons, Br Holstein

Barry R 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

Isospin Mixing And Model Dependence, Es Na, Br Holstein

Barry R Holstein

Anomalies In Quantum Mechanics: The 1/R(2) Potential, Sa Coon, Br Holstein

Barry R Holstein