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The SU3 model and strong coupling
.4NNALS
OF PHYSICS:
Abstracts
32, 503-504
(1965)
of Papers
to Appear
in Future
Issues
The
SU, Model and Strong Coupling. C. DULLIOND, Institute for Theoretical Physics, IJniversity of Nijmegen, Nijmegen, The Netherlands The purpose of this paper is to obtain the hierarchy of energy levels of baryon resonant states in a baryon-scaler meson coupling model using strong coupling techniques. The ineraction in SW, invariant (unbroken) and is an arbitrary mixture of F- and D-type coupling, indicated by a mixing parameter 01. Certain specific values for 01 are excluded from consideration. The computation is done for the case of very strong coupling, such that all resonant states now appear as bound states. It is hoped that for weaker coupling the hierarchical order of levels is maintained. No low-lying singlet appears; the ground state is an octet. For 0 < 01 < !s there is a low-lying deeuplet level fairly constant in that interval as compared to the octet level and minimal for (I = >L. There is a (27) which is maximal for 01 - !d. A (lo*} varies rapidly and is high for ?4 < 01 < fs. A (35) level is again fairly constant in the interval 0 < (T < f6 and rather low, but still higher t,han (27.) On the Equivalence of the Phenomena of the Meissner Effect and Injinite Conductivity in Superconductors. W. A. B. EVANS AND G. RICKAYZEN, The University of Liverpool, Department of Theoretical Physics, The Chadwick Laboratory, The University, Liverpool, England. It is shown that under certain general conditions a metal will show either both infinite conductivity and a Meissner effect in weak magnetic fields or neither. It is further shown that, provided phonon scattering and/or impurity scattering are present, both superconductors described by the BCS model and normal metals satisfy these conditions. Hence, it is concluded that superconductors possess both properties and normal metals neither. It is also concluded that the number of superconducting electrons defined by the Meissner Effect is equal in general to the number of electrons freely accelerated by an electric field. The Structure of the Distributions in Local Field Theory and the Asymptotic Behavior of Scattering Amplitudes. NGUYEN T’. HIEU, Joint Institute for Nuclear Research, Moscow, U.S.S.R. A new class of distributions which is wider than the class of tempered distributions and is suitable for formulating the microcausality principle in the local field theory is considered. It is proved that, owing to the microcausality principle and the local character of t,he fields, the scattering amplitudes increase slower than any linear exponential when energy tends to infinity in the complex plane. Some physical consequences of this behaviour are also considered. The Scattering of Plane Waves from Periodic Surfaces. J. L. URETSKY, High Energy Physics Division (362), Argonne National Laboratory, Argonne, Illinois. The reflection of scalar plane waves from periodic surfaces (in two dimensions) is studied. ParticuIar attention is devoted to the sinusoidal surface upon which the wave function fanishes. The formulation of the problem rests upon Green’s theorem, and it is shown that 503
OF PHYSICS:
Abstracts
32, 503-504
(1965)
of Papers
to Appear
in Future
Issues
The
SU, Model and Strong Coupling. C. DULLIOND, Institute for Theoretical Physics, IJniversity of Nijmegen, Nijmegen, The Netherlands The purpose of this paper is to obtain the hierarchy of energy levels of baryon resonant states in a baryon-scaler meson coupling model using strong coupling techniques. The ineraction in SW, invariant (unbroken) and is an arbitrary mixture of F- and D-type coupling, indicated by a mixing parameter 01. Certain specific values for 01 are excluded from consideration. The computation is done for the case of very strong coupling, such that all resonant states now appear as bound states. It is hoped that for weaker coupling the hierarchical order of levels is maintained. No low-lying singlet appears; the ground state is an octet. For 0 < 01 < !s there is a low-lying deeuplet level fairly constant in that interval as compared to the octet level and minimal for (I = >L. There is a (27) which is maximal for 01 - !d. A (lo*} varies rapidly and is high for ?4 < 01 < fs. A (35) level is again fairly constant in the interval 0 < (T < f6 and rather low, but still higher t,han (27.) On the Equivalence of the Phenomena of the Meissner Effect and Injinite Conductivity in Superconductors. W. A. B. EVANS AND G. RICKAYZEN, The University of Liverpool, Department of Theoretical Physics, The Chadwick Laboratory, The University, Liverpool, England. It is shown that under certain general conditions a metal will show either both infinite conductivity and a Meissner effect in weak magnetic fields or neither. It is further shown that, provided phonon scattering and/or impurity scattering are present, both superconductors described by the BCS model and normal metals satisfy these conditions. Hence, it is concluded that superconductors possess both properties and normal metals neither. It is also concluded that the number of superconducting electrons defined by the Meissner Effect is equal in general to the number of electrons freely accelerated by an electric field. The Structure of the Distributions in Local Field Theory and the Asymptotic Behavior of Scattering Amplitudes. NGUYEN T’. HIEU, Joint Institute for Nuclear Research, Moscow, U.S.S.R. A new class of distributions which is wider than the class of tempered distributions and is suitable for formulating the microcausality principle in the local field theory is considered. It is proved that, owing to the microcausality principle and the local character of t,he fields, the scattering amplitudes increase slower than any linear exponential when energy tends to infinity in the complex plane. Some physical consequences of this behaviour are also considered. The Scattering of Plane Waves from Periodic Surfaces. J. L. URETSKY, High Energy Physics Division (362), Argonne National Laboratory, Argonne, Illinois. The reflection of scalar plane waves from periodic surfaces (in two dimensions) is studied. ParticuIar attention is devoted to the sinusoidal surface upon which the wave function fanishes. The formulation of the problem rests upon Green’s theorem, and it is shown that 503