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Are quarks fractionally or integrally charged?
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Particle-Hole Excitations with a Cowlplete Single Particle Basis. A. AGODI, F. CANT~H.~, and M. DITORO, Instituto di Fisica dell’universita, Corso Italia 57, Catania, Italy. The truncated set of single-particle wave functions commonly used in nuclear spectroscopic TD calculations has been completed so as to allow the construction of a complete set of particle-hole states. In the space spanned by such states the method of the equivalent problem in a subpace has been applied t,o get the discrete spectrum of O-, I-, and 3particle-hole excitations in Cl2 and 0’6, by using explicitly given projection operators and a suitably simplified extension of the standard TD hamiltonian wit,h zero range two-body interactions. The here-defined extended TD approximation gives, as expected on general grounds, eigenvalues lower than the corresponding ones obtained in the usual TD approximation: but the shift never exceeds 1 MeV in the considered cases. The main effect of the ext,ension has therefore to be read in the wave function-dependent properties of the states, whose invest,igation is deferred to a second paper. Poincare Invariance, Particle Fields, and Internal Sywlmetry. G. FELDMAN and P. T. METTHEWS, Department of Physics, Imperial College of Science and Technology, Prince Consort Road, South Kensington, London S.W. 7, England. Following Weinberg, we develop the use of finite nonunitary representations of a noncompact auxiliary group to construct local fields, corresponding to particles which belong to infinite unitary representations of the Poincare group. It is shown how these auxiliary groups are extended to form a basis for theories such as 8(12), which can be used to build additional restrictions into a theory, without actually extending the invariance beyond the outer product of the Poincare group with the internal symmetry group. This is done in a covariant manner, which preserves crossing symmetry and CPT invariance, although the restrictions imposed refer physically to the static limit. Are Quarks Fractionally or Integrally Charged? M. P. KHANNA and S. OHUBO, International Center for Theoretical Physics, Piazza Oberdan 6, Trieste, Italy. On the basis of algebra of currents, we have computed the decay rate ao + 27 and the axial Vector renormahation constant QA . These numbers are model-dependent,, and we find that the fractionally charged quark model gives us more satisfactory results than the integrally charged quark model. s- and p-Wave Neutron Spectroscopy. Part IIIb. Area Analysis of Neutron Resonances Including E$ect of Doppler Broadening. K. K. SETH and R. H. TsBONY, Department of Physics, Northwestern University, Evanston, Illinois. The method of area analysis of neutron resonances observed in transmission experiments has been extended to include the effect of Doppler-broadening of these resonances. A BreitWigner single-level formula including interference between resonance scattering and potential scattering was assumed for t,he total cross section. General Nondynamical Formalism for Reactions with Particles of Arbitrary Spin: Rotation Invariance. PAUL L. CSONKA, MICHAEL J. MORAVCSIK, and MICHAEL D. SCADRON, Lawrence Radiation Laboratory, University of California, Livermore, California. The purpose of this paper is to give a detailed and practical prescription for calculating physical observables from form-factors (i.e., invariant amplitudes) of the M-matrix for an arbitrary reaction containing an arbitrary number of particles having arbitrary spins. The treatment is fully relativistic. No invariance principles have been assumed (except
ABSTRACTS
OF
PAPERS
TO
APPEAR
IN
FUTURE
ISSUES
Particle-Hole Excitations with a Cowlplete Single Particle Basis. A. AGODI, F. CANT~H.~, and M. DITORO, Instituto di Fisica dell’universita, Corso Italia 57, Catania, Italy. The truncated set of single-particle wave functions commonly used in nuclear spectroscopic TD calculations has been completed so as to allow the construction of a complete set of particle-hole states. In the space spanned by such states the method of the equivalent problem in a subpace has been applied t,o get the discrete spectrum of O-, I-, and 3particle-hole excitations in Cl2 and 0’6, by using explicitly given projection operators and a suitably simplified extension of the standard TD hamiltonian wit,h zero range two-body interactions. The here-defined extended TD approximation gives, as expected on general grounds, eigenvalues lower than the corresponding ones obtained in the usual TD approximation: but the shift never exceeds 1 MeV in the considered cases. The main effect of the ext,ension has therefore to be read in the wave function-dependent properties of the states, whose invest,igation is deferred to a second paper. Poincare Invariance, Particle Fields, and Internal Sywlmetry. G. FELDMAN and P. T. METTHEWS, Department of Physics, Imperial College of Science and Technology, Prince Consort Road, South Kensington, London S.W. 7, England. Following Weinberg, we develop the use of finite nonunitary representations of a noncompact auxiliary group to construct local fields, corresponding to particles which belong to infinite unitary representations of the Poincare group. It is shown how these auxiliary groups are extended to form a basis for theories such as 8(12), which can be used to build additional restrictions into a theory, without actually extending the invariance beyond the outer product of the Poincare group with the internal symmetry group. This is done in a covariant manner, which preserves crossing symmetry and CPT invariance, although the restrictions imposed refer physically to the static limit. Are Quarks Fractionally or Integrally Charged? M. P. KHANNA and S. OHUBO, International Center for Theoretical Physics, Piazza Oberdan 6, Trieste, Italy. On the basis of algebra of currents, we have computed the decay rate ao + 27 and the axial Vector renormahation constant QA . These numbers are model-dependent,, and we find that the fractionally charged quark model gives us more satisfactory results than the integrally charged quark model. s- and p-Wave Neutron Spectroscopy. Part IIIb. Area Analysis of Neutron Resonances Including E$ect of Doppler Broadening. K. K. SETH and R. H. TsBONY, Department of Physics, Northwestern University, Evanston, Illinois. The method of area analysis of neutron resonances observed in transmission experiments has been extended to include the effect of Doppler-broadening of these resonances. A BreitWigner single-level formula including interference between resonance scattering and potential scattering was assumed for t,he total cross section. General Nondynamical Formalism for Reactions with Particles of Arbitrary Spin: Rotation Invariance. PAUL L. CSONKA, MICHAEL J. MORAVCSIK, and MICHAEL D. SCADRON, Lawrence Radiation Laboratory, University of California, Livermore, California. The purpose of this paper is to give a detailed and practical prescription for calculating physical observables from form-factors (i.e., invariant amplitudes) of the M-matrix for an arbitrary reaction containing an arbitrary number of particles having arbitrary spins. The treatment is fully relativistic. No invariance principles have been assumed (except