Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 30 of 75
Full-Text Articles in Physical Sciences and Mathematics
Graviton-Photon Scattering, N.E.J. Bjerrum-Bohr, Barry R. Holstein, Ludovic Planté, Pierre Vanhove
Graviton-Photon Scattering, N.E.J. Bjerrum-Bohr, Barry R. Holstein, Ludovic Planté, Pierre Vanhove
Barry R Holstein
We use the feature that the gravitational Compton scattering amplitude factorizes in terms of Abelian QED amplitudes to evaluate various gravitational Compton processes. We examine both the QED and gravitational Compton scattering from a massive spin-1 system by the use of helicity amplitude methods. In the case of gravitational Compton scattering we show how the massless limit can be used to evaluate the cross section for graviton-photon scattering and discuss the difference between photon interactions and the zero mass spin-1 limit. We show that the forward scattering cross section for graviton photoproduction has a very peculiar behavior, differing from the …
Bending Of Light In Quantum Gravity, N.E.J. Bjerrum-Bohr, John F. Donoghue, Barry R. Holstein, Ludovic Planté, Pierre Vanhove
Bending Of Light In Quantum Gravity, N.E.J. Bjerrum-Bohr, John F. Donoghue, Barry R. Holstein, Ludovic Planté, Pierre Vanhove
Barry R Holstein
We consider the scattering of lightlike matter in the presence of a heavy scalar object (such as the Sun or a Schwarzschild black hole). By treating general relativity as an effective field theory we directly compute the nonanalytic components of the one-loop gravitational amplitude for the scattering of massless scalars or photons from an external massive scalar field. These results allow a semiclassical computation of the bending angle for light rays grazing the Sun, including long-range ℏ contributions. We discuss implications of this computation, in particular the violation of some classical formulations of the equivalence principle.
Chiral Perturbation Theory And Nucleon Polarizabilities, Br Holstein
Chiral Perturbation Theory And Nucleon Polarizabilities, Br Holstein
Barry R Holstein
Compton scattering offers in principle an intriguing new window on nucleon structure. Existing experiments and future programs are discussed and the state of theoretical understanding of such measurements is explored.
Semileptonic Decays Of The Light J(P)=1/2(+) Ground State Baryon Octet, A Faessler, T Gutsche, Br Holstein, Ma Ivanov, Jg Korner, Ve Lyubovitskij
Semileptonic Decays Of The Light J(P)=1/2(+) Ground State Baryon Octet, A Faessler, T Gutsche, Br Holstein, Ma Ivanov, Jg Korner, Ve Lyubovitskij
Barry R Holstein
We calculate the semileptonic baryon octet-octet transition form factors using a manifestly Lorentz covariant quark model approach based on the factorization of the contribution of valence quarks and chiral effects. We perform a detailed analysis of SU(3)-breaking corrections to the hyperon semileptonic decay form factors. We present complete results on decay rates and asymmetry parameters including lepton mass effects for the rates.
Generalized Polarizabilities And The Chiral Structure Of The Nucleon, Thomas R. Hemmert, Barry R. Holstein, Germar Knöchlein, Stefan Scherer
Generalized Polarizabilities And The Chiral Structure Of The Nucleon, Thomas R. Hemmert, Barry R. Holstein, Germar Knöchlein, Stefan Scherer
Barry R Holstein
No abstract provided.
Parity-Violating Photoproduction Of Pi(+/-) On The Delta Resonance, Sl Zhu, Cm Maekawa, Br Holstein, Mj Ramsey-Musolf
Parity-Violating Photoproduction Of Pi(+/-) On The Delta Resonance, Sl Zhu, Cm Maekawa, Br Holstein, Mj Ramsey-Musolf
Barry R Holstein
We analyze the real-photon asymmetry Aγ± for the parity-violating (PV) π± production on the Δ resonance via the reactions γ⃗+p→Δ+→π++n and γ⃗+d→Δ0+p→π-+p+p. This asymmetry is nonvanishing due to a PV γNΔ coupling constant, dΔ±. We argue that an experimental determination of this coupling would be of interest for hadron dynamics, possibly shedding light on the S-wave/ P-wave puzzle in the hyperon nonleptonic decays and the violation of Hara’s theorem in weak radiative hyperon decays.
Hadronic Atoms And Effective Interactions, Br Holstein
Hadronic Atoms And Effective Interactions, Br Holstein
Barry R Holstein
We examine the problem of hadronic atom energy shifts using the technique of effective interactions and demonstrate the equivalence with the conventional quantum mechanical approach.
K(S)-]Gamma-Gamma, K(L)-]Pi(0)Gamma-Gamma And Unitarity, J Kambor, Br Holstein
K(S)-]Gamma-Gamma, K(L)-]Pi(0)Gamma-Gamma And Unitarity, J Kambor, Br Holstein
Barry R Holstein
Agreement between the experimental value Γ(KS→γγ) and the number predicted via a one-loop chiral perturbation theory calculation has been cited as a success for the latter. On the other hand the one-loop prediction for the closely related process KL→π0γγ has been found to be a factor 3 below the experimental value. Using the inputs of unitarity and dispersion relations, we demonstrate the importance of higher order loop effects to both of these processes.
Is Su(3) Chiral Perturbation Theory An Effective Field Theory?, Br Holstein
Is Su(3) Chiral Perturbation Theory An Effective Field Theory?, Br Holstein
Barry R Holstein
We argue that the difficulties associated with the convergence properties of conventional SU(3) chiral perturbation theory can be ameliorated by use of a cutoff, which suppresses the model-dependent short distance effects in such calculations.
Spin Effects In Long Range Electromagnetic Scattering, Br Holstein, Andreas Ross
Spin Effects In Long Range Electromagnetic Scattering, Br Holstein, Andreas Ross
Barry R Holstein
We analyze the electromagnetic scattering of massive particles with and without spin and, using the techniques of effective field theory, we isolate the leading long distance effects beyond one photon exchange, both classical and quantum mechanical. Spin-independent and spin-dependent effects are isolated and shown to have a universal structure.
A Status Report On Chiral Dynamics: Theory And Experiment, Aron M. Benstein, Barry Holstein
A Status Report On Chiral Dynamics: Theory And Experiment, Aron M. Benstein, Barry Holstein
Barry R Holstein
This paper gives an overview of a Workshop on Chiral Dynamics: Theory and Experiment which was held at MIT July 25-29, 1994; its unique feature was the equal mixture of theory and experiment. The purpose of the workshop was to bring together many of the active participants to assess the status of the field and to explore fruitful future directions. The foundations and present status of the theory were reviewed as well as the experimental status of the field. To facilitate the discussion of future directions working groups were organized on Threshold Photo/Electropion Production, Two-Pion Threshold and the Chiral Anomaly, …
Delta(1232) And The Polarizabilities Of The Nucleon, Tr Hemmert, Br Holstein, J Kambor
Delta(1232) And The Polarizabilities Of The Nucleon, Tr Hemmert, Br Holstein, J Kambor
Barry R Holstein
Previous calculations of the polarizabilities of the nucleon within the framework of heavy baryon chiral perturbation theory have included the contribution of the Δ(1232) only in its effects on various contact terms or have been performed in chiral SU(3) where systematic errors are difficult to control. Herein, we perform a corresponding calculation in chiral SU(2) wherein Δ(1232) is treated as an explicit degree of freedom and the expansion is taken to third order in soft momenta, the pion mass, and the quantity MΔ-MN, collectively denoted ε. We present the results of a systematic O(ε3) calculation of forward Compton scattering off …
Lowest Order Effective Field Theory For The Weak #3;N Interaction, A Parreno, C Bennhold, Br Holstein
Lowest Order Effective Field Theory For The Weak #3;N Interaction, A Parreno, C Bennhold, Br Holstein
Barry R Holstein
The $|\Delta S|=1$ $\Lambda N$ interaction, responsible for the decay of hypernuclei, is studied by means of an Effective Field Theory where the long range physics is described by pion and kaon exchange mechanisms, and its short range counterpart is obtained from the most general non-derivative local four-fermion interaction. We show that, including the Lowest Order Parity Conserving contact terms, allows us to reproduce the total decay rates for $^5_\Lambda {\rm He}$, $^{11}_\Lambda {\rm B}$ and $^{12}_\Lambda {\rm C}$ with a reasonable value of ${\hat \chi^2}$, while in order to get a prediction for the Parity Violating (PV) asymmetry compatible …
Low Energy Tests Of Chiral Symmetry1, Br Holstein
Low Energy Tests Of Chiral Symmetry1, Br Holstein
Barry R Holstein
The present status of low energy test of chiral invariance via chiral perturbation theory is reviewed, both in the meson and baryon sectors, and future prospects are discussed.
Subleading Corrections To Parity-Violating Pion Photoproduction, Sl Zhu, S Puglia, Br Holstein, Mj Ramsey-Musolf
Subleading Corrections To Parity-Violating Pion Photoproduction, Sl Zhu, S Puglia, Br Holstein, Mj Ramsey-Musolf
Barry R Holstein
We compute the photon asymmetry Bγ for near threshold parity-violating (PV) pion photoproduction through subleading order. We show that subleading contributions involve a new combination of PV couplings not included in previous analyses of hadronic PV. We argue that existing constraints on the leading order contribution to Bγ—obtained from the PV γ-decay of 18F—suggest that the impact of the subleading contributions may be more significant than expected from naturalness arguments.
Effective Field Theory In Nuclear Physics, Martin J. Savage, Br Holstein
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.
Resonances In Weak Nonleptonic Omega(-) Decay, B Borasoy, Br Holstein
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.
Photon-Photon Scattering, Pion Polarizability, And Chiral-Symmetry, Jf Donoghue, Br Holstein
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.
Generalized Polarizabilities And The Chiral Structure Of The Nucleon, Tr Hemmert, Br Holstein, G Knochlein, S Scherer
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).
Effective Field Theory And Xpt, Br Holstein
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.
Heavy Baryon Chiral Perturbation Theory With Light Deltas, Tr Hemmert, Br Holstein, J Kambor
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'.
Nucleon Anapole Moment And Parity-Violating Ep Scattering, Sl Zhu, Sj Puglia, Br Holstein, Mj Ramsey-Musolf
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.
Dispersion-Relations And The Nucleon Polarizability, Br Holstein, Am Nathan
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.
Compton Scattering And The Spin Structure Of The Nucleon At Low Energies, Tr Hemmert, Br Holstein, J Kambor, G Knochlein
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.
Introduction To Effective Field Theory, Br Holstein
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.
Role Of Resonances In Nonleptonic Hyperon Decays, B Borasoy, Br Holstein
Role Of Resonances In Nonleptonic Hyperon Decays, B Borasoy, Br Holstein
Barry R Holstein
We examine the importance of resonances for the nonleptonic hyperon decays in the framework of chiral perturbation theory. Lower lying resonances are included in the effective theory. Integrating out the heavy degrees of freedom in the resonance saturation scheme generates higher order counterterms in the effective Lagrangian, providing an estimate of the pertinent coupling constants. A fit to the eight independent decay amplitudes that are not related by isospin symmetry is performed and reasonable agreement for both s and p waves is achieved.
A Vision For Nuclear Theory, Joseph Carlson, Richard Casten, Barry Holstein, Et. Al
A Vision For Nuclear Theory, Joseph Carlson, Richard Casten, Barry Holstein, Et. Al
Barry R Holstein
This is the report of the NSAC Subcommittee on Nuclear Theory in response to a charge by the funding agencies to review and evaluate current NSF and DOE supported efforts in nuclear theory and identify strategic plans to ensure a strong U.S. nuclear theory program under various funding scenarios.
Chiral Perturbation Theory: A Primer, Br Holstein
Chiral Perturbation Theory: A Primer, Br Holstein
Barry R Holstein
Recently methods have been developed which exploit the chiral symmetry of QCD in order to make rigorous contact with low energy particle physics phenomenology. In these lectures we present a pedagogical introduction to these techniques.
Hyperon Physics—A Personal Overview, Br Holstein
Hyperon Physics—A Personal Overview, Br Holstein
Barry R Holstein
A range of issues in the field of hyperon physics is presented, together with an assessment of where important challenges remain.
Graviton Physics, Br Holstein
Graviton Physics, Br Holstein
Barry R Holstein
The interactions of gravitons with matter are calculated in parallel with the familiar photon case. It is shown that graviton scattering amplitudes can be factorized into a product of familiar electromagnetic forms. The cross sections for various reactions are evaluated straightforwardly using helicity methods.