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A Caltech Library Repository Feedhttp://www.rssboard.org/rss-specificationpython-feedgenenTue, 28 Nov 2023 18:27:48 +0000Wide-angle pair production and quantum electrodynamics at small distances
https://resolver.caltech.edu/CaltechAUTHORS:BJOpr58
Authors: Bjorken, J. D.; Drell, S. D.; Frautschi, S. C.
Year: 1958
DOI: 10.1103/PhysRev.112.1409
Wide-angle photoproduction of high-energy electron-positron pairs in hydrogen is proposed and analyzed as a test of quantum electrodynamics at distances ≤10^-13 cm. The effect of proton structure can be removed in terms of the two form factors measured in the elastic electron-proton scattering process. Cross sections are presented for two classes of pair production experiments: (1) those detecting one of the final particles, and (2) coincidence experiments. In addition to kinematic, anomalous moment, and nucleon form-factor corrections to the Bethe-Heitler formula, dynamical corrections to the proton current and radiative corrections are calculated. The final theoretical formula is believed to be accurate to 2%. A simple cutoff model suggests that a 5% accuracy in an experiment of type (1) tests the electron propagator at distances ∼0.7×10^-13 cm, while a 10% accuracy in a coincidence arrangement of type (2) probes the electron propagator at ∼0.3×10^-13 cm.https://authors.library.caltech.edu/records/t1qn5-aav69Sensitivity of low-energy pion-nucleon scattering to a pion-pion resonance
https://resolver.caltech.edu/CaltechAUTHORS:FRApr60a
Authors: Frautschi, S. C.
Year: 1960
DOI: 10.1103/PhysRevLett.5.159
Recently attention has been called to the possibility of explaining nucleon electromagnetic structure quantitatively by the introduction of a pion-pion resonance in the T = 1, J = 1 state.(1) Such a resonance should also affect pion-nucleon scattering.https://authors.library.caltech.edu/records/s5p98-q8216Pion-nucleon scattering in the Mandelstam representation
https://resolver.caltech.edu/CaltechAUTHORS:FRApr60b
Authors: Frautschi, S. C.; Walecka, J. D.
Year: 1960
DOI: 10.1103/PhysRev.120.1486
Using the analytic properties of partial wave scattering amplitudes, as derived from Mandelstam's representation, we have studied the J=3/2, P state of the pion-nucleon system. The method used is covariant, it incorporates unitarity, and the effect of a possible pion-pion resonance has been investigated. Using the "single nucleon term" and the low-energy scattering properties of the "crossed states," we obtain a resonance in the J=3/2, T=3/2 pion-nucleon state without the aid of a cutoff. We have also investigated the scattering in the T=1/2 state. The pion-pion resonance appears to have only a very small effect in the T=3/2 state whereas in the T=1/2 state it increases the phase shift by a factor of 2.
The resonance obtained in the T=3/2 state occurs at too low an energy. There are several factors which may account for this: We have not been able to include fully the contributions from crossed states, and we have not systematically included inelastic scattering.https://authors.library.caltech.edu/records/9qrxj-v1e20Unified approach to high- and low-energy strong interactions on the basis of the Mandelstam representation
https://resolver.caltech.edu/CaltechAUTHORS:CHEpr60
Authors: Chew, G. F.; Frautschi, S. C.
Year: 1960
DOI: 10.1103/PhysRevLett.5.580
We wish here to outline an approach to the theory of strong interactions, based on the Mandelstam representation, that treats high- and low-energy phenomena in a unified manner. Our approach, which will be described in detail elsewhere, extends somewhat the original program proposed by Mandelstam.(1)https://authors.library.caltech.edu/records/00342-ntb41Dynamical Theory for Strong Interactions at Low Momentum Transfers but Arbitrary Energies
https://resolver.caltech.edu/CaltechAUTHORS:CHEpr61a
Authors: Chew, Geoffrey F.; Frautschi, Steven C.
Year: 1961
DOI: 10.1103/PhysRev.123.1478
Starting from the Mandelstam representation, it is argued on physical grounds that "strips" along the boundaries of the double spectral regions are likely to control the physical elastic scattering amplitude for arbitrarily high energies at small momentum transfers. Pion-pion scattering is used as an illustration to show how the double spectral functions in the nearest strip regions may be calculated, and an attempt is made to formulate an approximate but "complete" set of dynamical equations. The asymptotic behavior of the solutions of these equations is discussed, and it is shown that if the total cross section is to approach a constant at large energies then at low energy the S-dominant ππ solution is inadmissible. A principle of "maximum strength" for strong interactions is proposed, and it is argued that such a principle will allow large low-energy phase shifts only for l<~lmax, where lmax~1.https://authors.library.caltech.edu/records/wrsvx-35y81Potential scattering as opposed to scattering associated with independent particles in the S-matrix theory of strong interactions
https://resolver.caltech.edu/CaltechAUTHORS:CHEpr61b
Authors: Chew, Geoffrey F.; Frautschi, Steven C.
Year: 1961
DOI: 10.1103/PhysRev.124.264
A definition of a relativistic generalized potential is given, suitable at arbitrary energies for a pair of particles whose elastic scattering amplitude satisfies the Mandelstam representation. It is shown that the generalized potential plays a role in the dynamics analogous to that of the ordinary nonrelativistic potential in a Schrodinger equation and determines the scattering to the same extent. Below the threshold for inelastic processes the generalized potential is real and its energy dependence in the elastic region is expected for certain particle combinations (such as the nucleon-nucleon) to be weak. In such cases one may uniquely define, for use in the Schrodinger equation, an energy-independent ordinary potential that coincides with the potential of Charap and Fubini (Abstr. 1960A01252). In general, when the potential is complex and energy-dependent the dynamical problem involves iteration of an integral equation deduced by Mandelstam (Abstr. 1959A04941). The generalized potential may be decomposed according to range and it is shown that keeping only the long-and medium-range parts, corresponding to transfer of one or two particles, is almost equivalent to the "strip approximation." Finally, a general definition is given of "pure potential scattering" as opposed to scattering associated with "independent" particles, either stable or unstable, and a variety of experimental situations are discussed with respect to this distinction, which is shown to be susceptible to experimental test.https://authors.library.caltech.edu/records/vp3a1-67r91Principle of equivalence for all strongly interacting particles within the S-matrix framework
https://resolver.caltech.edu/CaltechAUTHORS:CHEprl61
Authors: Chew, Geoffrey F.; Frautschi, S. C.
Year: 1961
DOI: 10.1103/PhysRevLett.7.394
The notion, inherent in Lagrangian field theory, that certain particles are fundamental while others are complex, is becoming less and less palatable for baryons and mesons as the number of candidates for elementary status continues to increase. Sakata has proposed that only the neutron, proton, and A are elementary,(1) but this choice is rather arbitrary, and strong-interaction consequences of the Sakata model merely reflect the established symmetries.https://authors.library.caltech.edu/records/vk10n-9sj22Regge trajectories and the principle of maximum strength for strong interactions
https://resolver.caltech.edu/CaltechAUTHORS:CHEprl62
Authors: Chew, Geoffrey F.; Frautschi, Steven C.
Year: 1962
DOI: 10.1103/PhysRevLett.8.41
In previous publications, the authors have discussed the possibility that strong interactions "saturate" the unitarity condition; i.e., that they have the maximum possible strength consistent with the unitarity and analyticity of the S matrix.(1) Our earlier discussion was confined to elastic scattering, however, and although the conjectured existence of Regge poles underlay our arguments, we did not at the time of the earlier work appreciate certain essential properties of these poles.https://authors.library.caltech.edu/records/f55p2-00228Regge poles in π-π scattering
https://resolver.caltech.edu/CaltechAUTHORS:CHEpr62a
Authors: Chew, Geoffrey F.; Frautschi, Steven C.; Mandelstam, Stanley
Year: 1962
DOI: 10.1103/PhysRev.126.1202
The connection between Regge poles, bound states and resonances, and asymptotic behavior in momentum transfer is reviewed within the framework of the analytically continued S matrix, and a convergent iteration procedure is given for calculating the position and residue of a Regge pole in terms of a given (generalized) potential. By examining the long-range potential in the ππ system, it is inferred that Regge poles should appear in the I=0 and I=1 states, and that the latter pole may be responsible for the ρ meson while the former may well dominate high-energy behavior at low-momentum transfer in the crossed channels. The connection of this possibility with forward coherent (diffraction) scattering in general is explored, and a number of experimental predictions are emphasized. Finally it is shown that the short-range forces due to exchange of 4, 6, ... pions are likely to be repulsive and must be included in some form if a consistent solution is to be achieved.https://authors.library.caltech.edu/records/shzpr-7mn22Experimental consequences of the hypothesis of Regge poles
https://resolver.caltech.edu/CaltechAUTHORS:FRApr62
Authors: Frautschi, S. C.; Gell-Mann, M.; Zachariasen, F.
Year: 1962
DOI: 10.1103/PhysRev.126.2204
In the nonrelativistic case of the Schrödinger equation, composite particles correspond to Regge poles in scattering amplitudes (poles in the complex plane of angular momentum). It has been suggested that the same may be true in relativistic theory. In that case, the scattering amplitude in which such a particle is exchanged behaves at high energies like sα(t)[sinπα(t)]-1, where s is the energy variable and t the momentum transfer variable. When t=tR, the mass squared of the particle, then α equals an integer n related to the spin of the particle. In contrast, we may consider the case of a field theory in which the exchanged particle is treated as elementary and we examine each order of perturbation theory. When n>1, we can usually not renormalize successfully; when n≤1 and the theory is renormalizable, then the high-energy behavior is typically sn(t-tR)-1φ(t). Thus an experimental distinction is possible between the two situations. That is particularly interesting in view of the conjecture of Blankenbecler and Goldberger that the nucleon may be composite and that of Chew and Frautschi that all strongly interacting particles may be composite dynamical combinations of one another. We suggest a set of rules for finding the high-energy behavior of scattering cross sections according to the Regge pole hypothesis and apply them to π-π, π-N, and N-N scattering. We show how these cross sections differ from those expected when there are "elementary" nucleons and mesons treated in renormalized perturbation theory. For the case of N-N scattering, we analyze some preliminary experimental data and find indications that an "elementary" neutral vector meson is probably not present. Various reactions are proposed to test the "elementary" or "composite" nature of other baryons and mesons. Higher energies may be needed than are available at present.https://authors.library.caltech.edu/records/fnfgc-pst03Regge poles and inelastic scattering at high energies
https://resolver.caltech.edu/CaltechAUTHORS:CONpr63
Authors: Contogouris, A. P.; Frautschi, S. C.; Wong, How-sen
Year: 1963
DOI: 10.1103/PhysRev.129.974
The Regge pole hypothesis is applied to some inelastic processes at high energies. Particular attention is given to production of pion-nucleon resonances N* in the reaction N+N→N+N*. Data on production of the I=1/2 resonances are interpreted in terms of exchange of the "Pomeranchuk" Regge pole which is believed to be responsible for the diffraction peaks in elastic reactions, and production of the 3-3 resonance is interpreted in terms of exchange of the pion Regge pole. The prediction is obtained that production and decay of the I=1/2 resonances provides secondary pions and neutrons with energies that rise proportionally to the incident proton energy—a result of interest in connection with the secondary beams in future accelerators.https://authors.library.caltech.edu/records/pb2va-vh197Octet Enhancement
https://resolver.caltech.edu/CaltechAUTHORS:20150925-120547431
Authors: Dashen, Roger F.; Frautschi, Steven C.; Gell-Mann, Murray; Hara, Yasuo
Year: 1964
DOI: 10.1143/PTPS.29.135
A simple universal current-current theory of weak interactions now accounts fairly well for all weak phenomena except the nonleptonic │ΔI│ = 1/2 rule, which
presumably should be generalized to a unitary octet rule, covering not only the familiar │ΔY│ = 1 nonleptonic interactions but also the │ΔY│ =0 nonleptonic interactions
(for which experimental evidence in heavy nuclei has been presented by Boehm and Kankeleit).https://authors.library.caltech.edu/records/yjt38-5ay17Method for the Self-Consistent Determination of Regge Pole Parameters
https://resolver.caltech.edu/CaltechAUTHORS:FRApr64
Authors: Frautschi, S. C.; Kaus, P. E.; Zachariasen, F.
Year: 1964
DOI: 10.1103/PhysRev.133.B1607
A method is suggested for approximately bootstrapping Regge trajectories, thereby avoiding the cutoff problems of the usual bootstrap calculation. The method is based on dispersion relations for Regge trajectories and on unitarity applied at l=α. Successively more realistic approximations are described which bring in more information on the potential, and more trajectories. The approximate Regge parameters are guaranteed to have the desired threshold and asymptotic properties.https://authors.library.caltech.edu/records/qemsg-rjn49Neutrino astronomy and intermediate bosons
https://resolver.caltech.edu/CaltechAUTHORS:BAHpr64a
Authors: Bahcall, John N.; Frautschi, Steven C.
Year: 1964
DOI: 10.1103/PhysRev.135.B788
Neutrino fluxes from strong radio sources are estimated, assuming the neutrino-production mechanism: p+p→nucleons+mesons→nucleons+electrons, gamma rays, and neutrinos. The neutrino fluxes calculated on the basis of this mechanism are too small to be easily detected unless there are resonances in neutrino processes associated with the production of intermediate bosons. It is shown that a resonance in the antineutrino-electron system, associated with the usually hypothesized W- resonance, could be used to test, with standard experimental techniques, whether strong radio sources emit high-energy neutrinos in the quantities estimated in this paper. Two kinds of observational tests are described and counting rates are estimated. Observational tests of the kind we propose would provide important information about: (1) the mechanism for production of high-energy electrons in strong radio sources, and (2) the magnetic fields in such sources. Some comments concerning other logically possible neutrino resonances are also included.https://authors.library.caltech.edu/records/byv6h-wqe19S-matrix method for calculation of electromagnetic corrections to strong interactions
https://resolver.caltech.edu/CaltechAUTHORS:DASpr64c
Authors: Dashen, Roger F.; Frautschi, Steven C.
Year: 1964
DOI: 10.1103/PhysRev.135.B1190
We develop an S-matrix method for calculating the effect of small perturbations on a partial-wave amplitude, and in particular, on the positions and residues of bound states. The method is applicable to both nonrelativistic and relativistic problems. It has, as a particular virtue, rapid convergence of the dispersion integrals. Electromagnetic corrections to strong interactions are the main application we have in mind, and modifications useful for handling the infrared divergence that occurs in this case are described in detail.https://authors.library.caltech.edu/records/gf4dd-t5567Bootstrap theory of octet enhancement
https://resolver.caltech.edu/CaltechAUTHORS:DASprl64b
Authors: Dashen, R.; Frautschi, S.
Year: 1964
DOI: 10.1103/PhysRevLett.13.497
Recently it has become apparent that many violations of SU(3) follow an octet pattern. For example, (i) the Gell-Mann-Okubo sum rule(1,2) represents the main features of strong mass splittings among members of a supermultiplet, indicating that the splittings transform like the eighth component of an octet; (ii) the electromagnetic mass splittings within the baryon isospin multiplets seem to transform mostly like the third component of an octet3; (iii) nonleptonic weak decays also seem to be dominantly octet in view of the |ΔI|=½ rule.(4)https://authors.library.caltech.edu/records/ahyj8-m9264Neutrino Opacity. II. Neutrino-Nucleon Interactions
https://resolver.caltech.edu/CaltechAUTHORS:20120815-110844801
Authors: Bahcall, John N.; Frautschi, Steven C.
Year: 1964
DOI: 10.1103/PhysRev.136.B1547
The contribution of neutrino-nucleon interactions to the neutrino opacity of matter is studied, special attention being paid to possible astrophysical applications such as supernova explosions. The results of recent accelerator experiments with high-energy neutrinos are used to show that nonresonant neutrino-nucleon scattering does not make a significant contribution to the neutrino opacity for astrophysically important conditions. The results of deep-mine cosmic-ray studies are then used to show that, (a) there are no resonances in the ν_μ-nucleon and ν̅ _μ-nucleon systems with masses less than 60 BeV (laboratory neutrino energies <2×10^(+3) BeV), and (b) there are no resonances in the ν_(e)-neucleon and ν̅_(e)-nucleon systems with masses less than 7 BeV (laboratory neutrino energies <30 BeV). Neutrino absorption by bound nucleons is also discussed and a sum rule is proved for neutrino capture that is sufficiently accurate for most astrophysical applications. The effect of the exclusion principle on the capture cross sections is described and some applications to specific nuclei are presented. The accelerator experiments with high-energy neutrinos are then used to show that neutrino radioactivity, i.e., nuclear de-excitation by emission of a neutrino-antineutrino pair, is a substantially less important mechanism for stellar energy loss than was suggested by some previous estimates.https://authors.library.caltech.edu/records/3g6dr-fsj65Experimental Restrictions on Ne'eman's Fifth Interaction
https://resolver.caltech.edu/CaltechAUTHORS:BEDpr64
Authors: Beder, D.; Dashen, R.; Frautschi, S.
Year: 1964
DOI: 10.1103/PhysRev.136.B1777
Recently, Ne'eman has proposed a "fifth interaction" between the strangeness current and a neutral vector meson χ, for the purpose of breaking SU(3) symmetry. We show that a χ mass less than 2mπ would be inconsistent with a variety of experiments, including K-mesonic atoms, the long-range pp potential, K1 regeneration from a K2 beam, the Lamb shift, modern refinements of the Cavendish "ice-bucket" experiment, and the absence of π0→γ+χ and χ→e++e-. The remaining possibility, that mχ exceeds 2mπ, is discussed briefly.https://authors.library.caltech.edu/records/znc5j-08a71Bootstrap theory and the parity-nonconserving decays of the hyperons
https://resolver.caltech.edu/CaltechAUTHORS:DASprl64a
Authors: Dashen, R. F.; Frautschi, S. C.; Sharp, D. H.
Year: 1964
DOI: 10.1103/PhysRevLett.13.777
In a recent series of publications,(1-4) a general "bootstrap" theory of octet enhancement in the strong, electromagnetic, and (parity-conserving) weak violations of SU(3) symmetry has been proposed. The theory was successfully applied(4) to the strong and electromagnetic mass splittings in the 1/2+ octet and the 3/2+ decuplet of baryons.https://authors.library.caltech.edu/records/n4vz6-ctq82Octet enhancement in the B and Δ supermultiplets
https://resolver.caltech.edu/CaltechAUTHORS:DASpr65a
Authors: Dashen, Roger F.; Frautschi, Steven C.
Year: 1965
DOI: 10.1103/PhysRev.137.B1331
The bootstrap theory of octet enhancement is described in general, and applied in particular to strong and electromagnetic mass splittings within the JP=1/2+ baryon octet and J=3/2+ decuplet. The results are in good agreement with experiment.https://authors.library.caltech.edu/records/3h0y6-gcq14General S-Matrix Methods for Calculation of Perturbations on
the Strong Interactions
https://resolver.caltech.edu/CaltechAUTHORS:20120817-153357306
Authors: Dashen, Roger F.; Frautschi, Steven C.
Year: 1965
DOI: 10.1103/PhysRev.137.B1318
Recently, the authors proposed an on-the-mass-shell, S-matrix method for computing the effects of small perturbations on the masses and coupling constants of strongly interacting particles. In the present paper, the method is generalized to the multichannel case. The use of group-theoretical techniques in reducing the complexity of the method is described in detail.https://authors.library.caltech.edu/records/bw24x-9x385Some general features of the bootstrap theory of octet enhancement
https://resolver.caltech.edu/CaltechAUTHORS:DASpr65d
Authors: Dashen, Roger F.; Frautschi, Steven C.
Year: 1965
DOI: 10.1103/PhysRev.140.B698
Some general features of the boostrap theory of octet enhancement, which can be understood without detailed calculations, are discussed. These features include: (i) the connection of this theory to the vector-mixing theory of symmetry breaking advocated by Sakurai, and to the tadpole theory of Coleman and Glashow; (ii) an understanding of why it is representations of low multiplicity that are dynamically emphasized in symmetry breaking; (iii) a demonstration that the theory remains valid when a number of assumptions made in previous applications are dropped.https://authors.library.caltech.edu/records/2c25f-z8q57Self-Consistent Determination of Coupling Shifts in Broken SU(3)
https://resolver.caltech.edu/CaltechAUTHORS:20120820-101710400
Authors: Dashen, R. F.; Dothan, Y.; Frautschi, S. C.; Sharp, D. H.
Year: 1966
DOI: 10.1103/PhysRev.143.1185
The possibility that certain patterns of SU(3) symmetry breaking are dynamically enhanced in baryon-meson couplings is studied by bootstrap methods. For the strong couplings, a single dominant enhancement is found. It produces very large symmetry-breaking terms, transforming like an octet, as often conjectured. Experimental consequences are listed, such as a reduction of K-baryon couplings relative to π-baryon couplings which is in accord with the experimental weakness of K relative to π production in many circumstances, such as photoproduction and multi-BeV cosmic-ray collisions. For parity-violating nonleptonic couplings, a dominant octet enhancement is again found, as mentioned in a previous paper, which leads to an excellent fit with experiment. For parity-conserving nonleptonic couplings, on the other hand, several different enhancements compete, and the only conclusion we can draw is that terms with the "abnormal" transformation properties brought in by strong symmetry-breaking corrections are present. Our work provides a dynamical derivation of various phenomenological facts associated with SU(6), such as the dominance of the 35 representation in parity-violating nonleptonic decays.https://authors.library.caltech.edu/records/4vzk4-96n79Weak and electromagnetic interactions of the hadrons in bootstrap theory
https://resolver.caltech.edu/CaltechAUTHORS:DASpr66a
Authors: Dashen, R. F.; Frautschi, S. C.
Year: 1966
DOI: 10.1103/PhysRev.143.1171
This is the first of a series of papers on the properties of the weak and electromagnetic currents of the hadrons in the bootstrap theory of strong interactions. In a bootstrap theory, there are many self-consistency conditions relating these weak and electromagnetic parameters to each other. We develop a formalism designed to take the fullest advantage of such bootstrap-like relations. In fact, we conjecture that the weak and electromagnetic properties of the hadrons are determined to a large extent, and perhaps completely, by self-consistency requirements. Some simple calculations of the weak and electromagnetic parameters pertaining to the octet of baryons and decuplet of resonances are given. The comparison of the results of these calculations with the experimental numbers indicates that the above conjecture holds, at least in this case.https://authors.library.caltech.edu/records/g9z06-7pz10Current Algebras and Symmetries in Bootstrap Theory
https://resolver.caltech.edu/CaltechAUTHORS:20120820-125920064
Authors: Dashen, R. F.; Frautschi, S. C.
Year: 1966
DOI: 10.1103/PhysRev.145.1287
In the first paper of this series we showed how, in the bootstrap theory, the currents associated with the
hadrons could be determined from a set of self-consistency conditions. In the present paper we show that
these "self-consistent" currents satisfy a current algebra. The proof is accomplished without recourse to any
approximate model It includes the interesting case of nonconserved currents. The convergence of sum rules
derived from current algebras is investigated in detail, and shown to be most rapid when no "nonbootstrap"
terms are present. Using these convergence properties, we discuss how and when current algebras can give
rise to hadron symmetries.https://authors.library.caltech.edu/records/qhegh-r0q05Regge Trajectories and Minima in Differential Cross Sections
https://resolver.caltech.edu/CaltechAUTHORS:FRAprl66
Authors: Frautschi, Steven
Year: 1966
DOI: 10.1103/PhysRevLett.17.722
Attempts to fit [1] the earliest accurate measurements of high-energy cross sections, namely the total cross sections and diffraction peaks, by Regge poles have not been totally convincing because a number of high-spin trajectories contribute, and the theory involves a correspondingly large number of parameters. Some of the smaller cross sections now being measured, however, can be described in terms of only one or two trajectories, thus providing a cleaner test of Regge theory [2-4].https://authors.library.caltech.edu/records/qj3ym-58t14Self-Consistent Determination of Coupling Shifts in Broken SU(3). II
https://resolver.caltech.edu/CaltechAUTHORS:20120921-134907994
Authors: Dashen, R. F.; Dothan, Y.; Frautschi, S. C.; Sharp, D. H.
Year: 1966
DOI: 10.1103/PhysRev.151.1127
In a recent paper, we considered the possibility of dynamical enhancement of SU(3) symmetry breaking in baryon couplings. It was found that certain patterns of symmetry breaking are enhanced and tend to dominate; the results were presented and compared with experiment. In the present companion paper, we explain in detail the methods by which these conclusions were obtained and give a more complete summery of the numerical results.https://authors.library.caltech.edu/records/kceje-qk711Chew-Low model for Regge-pole couplings
https://resolver.caltech.edu/CaltechAUTHORS:DASpr66e
Authors: Dashen, Roger; Frautschi, Steven
Year: 1966
DOI: 10.1103/PhysRev.152.1450
The couplings of a meson trajectory α(t) to the baryon octet B and the decimet Δ are studied in the Chew-Low model. The model predicts ratios, though not absolute magnitudes, for SU(3)-symmetric couplings of the 0- octet Π, 1- octet V, and 2+ octet T trajectories at the small t of either sign for which static kinematics is applicable. For non-spin-flip, the V and T trajectories are predicted to couple to B̅ B like F+1 / 4D, independent of t. For magnetic dipole terms, the Π, V, and T trajectories are all predicted to couple to B̅ B like D+2 / 3F, and to Δ̅ B with the same relative strength as the 0- octet, independent of t. The electric quadrupole couplings of the Π, V, and T trajectories are predicted to be small, independent of t. These results generally agree with existing data, improve Sawyer's explanation of the Johnson-Treiman relations, provide a partial justification of the recent suggestion that V and T couplings are similar, predict that T exchange produces large spin flips, and predict certain ratios such as dσ / dt(π-p→π0n) / (dσ / dt)(π+p→π0N*++).https://authors.library.caltech.edu/records/60f40-8qx21Small-Angle Photoproduction and Conspiracy
https://resolver.caltech.edu/CaltechAUTHORS:FRApr67a
Authors: Frautschi, Steven; Jones, Lorella
Year: 1967
DOI: 10.1103/PhysRev.163.1820
In any reaction of the class π+B→V+B, or V+B→π+B, nonconspiring amplitudes with a meson helicity change (hV-hπ≠0) exhibit a dip at small angles. Normally, this would simply mean that the zero-helicity-change amplitude dominates forward production. But in photoproduction, since the photon has no longitudinal component, there is no zero-helicity-change amplitude, and in the absence of conspiracy a forward dip will appear in the differential cross section. When conspiracy is present, the dip does not appear. Thus, forward photoproduction provides a good test for conspiracy.https://authors.library.caltech.edu/records/rhwtt-zne21Reggeization of Pion Exchange in Production Processes
https://resolver.caltech.edu/CaltechAUTHORS:FRApr67b
Authors: Frautschi, Steven; Jones, Lorella
Year: 1967
DOI: 10.1103/PhysRev.164.1918
Couplings of the pion Regge trajectory are discussed. We find that the kinematic factors prescribed by Wang must be supplemented by further kinematic terms. A simple physical interpretation is given for these additional terms. Our considerations lead to a model of pion trajectory couplings, which is in reasonable agreement with those experiments on vector- and tensor-meson production in which pion exchange is expected to dominate the forward peak.https://authors.library.caltech.edu/records/gqj10-jkv20Conspiracy Relations in Vector-Meson Production
https://resolver.caltech.edu/CaltechAUTHORS:FRApr68
Authors: Frautschi, Steven; Jones, Lorella
Year: 1968
DOI: 10.1103/PhysRev.167.1335
We list the conspiracy relations for reactions of type Π+N→V+N and Π+N→V+Δ, emphasizing that there are relations connecting states with opposite parity at t=0 even when all four masses are unequal. We show in detail that if the relations are satisfied by vanishing of the couplings of individual trajectories at t=0, all helicity-flip amplitudes are suppressed at forward angles; whereas if the relations are satisfied by conspiracy among various trajectories, the flip-flip amplitudes which conserve angular momentum in forward scattering can contribute with full strength.https://authors.library.caltech.edu/records/vaxns-ryg52Electromagnetic Perturbations on πNN and πNN* Couplings in the Chew-Low Model: General Features
https://resolver.caltech.edu/CaltechAUTHORS:BABpr68
Authors: Babu, P.; Frautschi, S.; Thornber, N. S.
Year: 1968
DOI: 10.1103/PhysRev.172.1389
Electromagnetic perturbations on πNN and πNN* couplings are studied in the N-N* reciprocal bootstrap model. In the present paper we confine ourselves to rather general features, making the linear-D approximation for simplicity. There are several self-consistent coupling shifts, much as in the analogous SU(3) reciprocal bootstrap. It is shown that, except for even-J exchanges in the t channel, the "driving terms" are orthogonal to these self-consistent coupling shifts. Thus, as in the SU(3) case, no simple predictions can be made for coupling shifts in the linear-D approximation.https://authors.library.caltech.edu/records/yrcph-8je23Selection rules for diffraction dissociation
https://resolver.caltech.edu/CaltechAUTHORS:CARprl69
Authors: Carlitz, R.; Frautschi, S.; Zweig, G.
Year: 1969
DOI: 10.1103/PhysRevLett.23.1134
The concept that internal quantum numbers do not change in diffractive production is extended to the quantum numbers of the quark model. The resulting approximate selection rules are discussed and compared with the predictions of other models.https://authors.library.caltech.edu/records/57cv2-46s02Eikonal Regge Model for Elastic Scattering Processes
https://resolver.caltech.edu/CaltechAUTHORS:FRAprd70
Authors: Frautschi, S. C.; Hamer, C. J.; Ravndal, F.
Year: 1970
DOI: 10.1103/PhysRevD.2.2681
The Frautschi-Margolis version of the Regge eikonal model is extended to include secondary Regge trajectories. Physical properties of the model are discussed. In particular, the "shrinkage" of dσ/dt observed at present energies (rapid shrinkage for pp and K+p, little or no shrinkage for π±p and K-p, antishrinkage for pp is related to the energy dependence of σtot pp and K+p nearly flat, π±p and K-p falling slowly, pp falling rapidly).https://authors.library.caltech.edu/records/5xdm1-pht38Statistical Bootstrap Model of Hadrons
https://resolver.caltech.edu/CaltechAUTHORS:FRAprd71
Authors: Frautschi, Steven
Year: 1971
DOI: 10.1103/PhysRevD.3.2821
The hadron is considered to be a compound with two or more constituents circulating freely in a box of radius ≈10^-13 cm. The density of hadron levels, ρ (m), is estimated from the number of states in the box (statistical condition) and is also required to be consistent with the spectrum of constituents, which are assumed to be the hadrons themselves (bootstrap condition). This type of model was first considered by Hagedorn, who obtained a solution of form ρ m∼cm^ae^(bm) with a=-5/2 which satisfied the bootstrap condition asymptotically to within a power of m. We obtain a solution with a<-5/2 which satisfies the bootstrap condition exactly in the high-mass limit. The constituents in the box are distributed with probability P(n)=(ln2)^(n-1)/(n-1)!; i.e., an average high-mass resonance decays (in the first generation of its decay chain) to two hadrons (69% probability) or three (24% probability). We also review briefly the thermodynamic applications of this model to high-energy scattering and astrophysics.https://authors.library.caltech.edu/records/8gn0r-ve108Determination of Asymptotic Parameters in the Statistical Bootstrap Model
https://resolver.caltech.edu/CaltechAUTHORS:HAMprd71
Authors: Hamer, C. J.; Frautschi, S. C.
Year: 1971
DOI: 10.1103/PhysRevD.4.2125
The statistical bootstrap model predicts that the density of hadron states ρ(m) approaches cmaebm asymptotically. We consider the consequences of extending the bootstrap condition in the model from asymptotic down to finite masses. This allows us to determine the parameters a, b, and c for various assignments of the hadron volume and low-mass input spectrum, and for the extreme cases of excluding all exotic particles or including all of them. In all cases, a=-3 for ρtot (summed over all internal quantum numbers). The parameter b varies somewhat from case to case but is always of order mπ^-1; thus we predict the maximum temperature T0=b^-1≈mπ in rough agreement with Hagedorn's empirical determination. The inclusion of exotic states has little effect on ρtot but does redistribute the partial level densities according to a simple rule. The predicted level densities (excluding exotic states) are compared with present data.https://authors.library.caltech.edu/records/m7tpw-c0b39Copious Direct Photon Production: A Possible Resolution of the Prompt-Lepton Puzzle
https://resolver.caltech.edu/CaltechAUTHORS:FARprl76
Authors: Farrar, Glennys R.; Frautschi, Steven C.
Year: 1975
DOI: 10.1103/PhysRevLett.36.1017
We propose that all direct leptons not due to vector meson decay can be attributed to the decay of virtual photons. At p⊥≈3 GeV/c, we expect γ / π, the ratio of direct photons to pions, to be about 10 to 20% for sqrt[s]≈20-60 GeV.https://authors.library.caltech.edu/records/ryc4h-2k473Stanley Mandelstam and my postdoctoral years at Berkeley
https://resolver.caltech.edu/CaltechAUTHORS:20170213-132930319
Authors: Frautschi, Steven
Year: 2017
DOI: 10.1142/S0217751X17400048
From 1959 to 1961 I was a postdoc at U.C. Berkeley. Personally, I regard my postdoctoral period as "Golden Years" – finished with course taking and thesis writing, not yet burdened with classes to teach, students to mentor, grants to apply for. Lots of freedom, lots of things to explore in the beautiful Bay Area.https://authors.library.caltech.edu/records/kwdbq-z4750