Separable single-particle Hamiltonian and its local equivalent

By using a method developed by Coz, Arnold and MacKellar the local equivalent of a single-particle potential discussed in a previous work is constructed and analyzed. The accuracy of the method is checked in the present case. The numerical examples refer to the low-energy elastic scattering of neutrons from nuclei described by a hole in a closed shell. The single-particle bound states are approximately described by harmonic oscillator wave functions. The results are similar to those derived by Coz, Arnold and MacKellar from non-local Hartree-Fock potentials.     

Ein Algorithmus zur Berechnung der Vielfachheiten von Gewichten

Zusammenfassung Es wird ein Algorithmus zur Berechnung der Vielfachheiten der Gewichte von Darstellungen halbeinfacher Lie-Gruppen angegeben, der auf der Division des Weyl'schen Quotienten für den Charakter beruht. Dabei wird diese Division im Stiefel-Diagramm geometrisch interpretiert.

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This paper is concerned with the multiplicities of the weights of representations of semisimple Lie groups. an algorithm for the calculation of these multiplicities using the division of Weyl's quotient for the character is given. By means of the Stiefel diagram this division is geometrically interpreted.

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Meinem verehrten Lehrer, Professor E. Stiefel gewidmet     

Upper critical fields of Nb∼3Au,Nb3Au0.7Pt0.3 and Nb3Pt

Upper critical field measurements of the A15 type compounds Nb_～3Au,Nb₃Au_0.7Pt_0.3 and Nb₃Pt having T_c values of 10.7, 13.0 and 8.7K, respectively, show H_c2(0) values of 235, 295 and 125 kG, respectively. The data for the compounds containing Au fit closely calculations for a dirty type II superconductor with no paramagnetic limiting, but data for Nb₃Pt are slightly above these calculations.     

Observation of the decay τ → πv

The decay of the heavy lepton τ into πv has been established using the magnetic detector PLUTO. The branching ratio is determined to be BR(τ→πv)=(9.0 ± 2.9)% with an additional systematic uncertainty of 2.5%. This value is in good agreement with the theoretical prediction.