[en] Strutinsky calculations are used to investigate the shape and fission stability of rotating nuclei at finite temperature. Pairing correlations are described within a modified BCS approach which allows for the inclusion of both thermal and rotational degrees of freedom. Numerical results are discussed for the case of the deformed nucleus ²⁴⁰Pu up to angular momentum I = 40(h/2π). The critical temperature T which characterizes the collapse of the pairing correlations is found to be of the order of Tsub(c) approx.= 0.40 MeV, for I = 0. (orig.)

[en] An analysis of multiply-charged projectile fragments has been performed from the point of view of fragmentation characteristics using a statistics of 916 fragments comprising over 923 interactions of ¹⁴N in emulsion at 2.1 GeV per nucleon. The number of interacting nucleons has been investigated in the light of the prediction of the participant-spectator model. The momentum of projectile fragments has been measured directly. Gaussian distributions have been fitted to the projected distributions as well as momentum distributions for multiply-charged projectile fragments at various intervals of impact parameter and in different reaction channels. Relativistic Maxwell-Boltzmann distributions have been fitted to the emission angles of He fragments, emitted in the collision with varius targets, to investigate the emission characteristics of relativistic projectile fragments. (orig.)

[en] The reactions ³⁵Cl + ⁵⁸Ni, ⁴⁰Ca, ²⁷Al are studied at 385 MeV bombarding energy. The experiment employs 6 large-area ionization chambers which are set up to detect fragments with nuclear charge Z >= 4 in coincidence multiplicity m <= 6. The highest multiplicity observed is m = 4; a detailed analysis of the data is performed for m = 2 and m = 3 events. The ⁵⁸Ni data contain reactions with 2 fragments (sigma = 1350 +- 500 mb) and 3 fragments (sigma = 175 +- 90 mb) in the exit channel. The three fragments appear to have their origin in two different processes: a sequential-fragmentation process and a fast break-up process. A similar conclusion is reached for the ²⁷Al data, whereas in the ⁴⁰Ca data only the sequential fragmentation could be identified. (orig.)

[en] The analysing power Asub(y0) of the pp -> πd reaction has been measured at SIN for four energies between 516 and 582 MeV with a statistical precision of better than 1%. Pions and deuterons have been detected in coincidence with scintillation detectors employing time-of-flight techniques for event identification. Using our data on the differential cross section sigma, Legendre polynomial expansion coefficients bsub(i)sup(y0) for the product sigmaAsub(y0) have been deduced for j = 1 to 5. The energy dependence of these coefficients has been compared with theoretical predictions. (orig.)

[en] Inelastic M3 form factors for the excitation of the 5.236 MeV 3⁺ state in ²⁴Mg and for the excitation of the 10.376 MeV 3⁺, T = 1 state in ²⁸Si have been measured. These form factors are compared with full 2s1d shell-model calculations in order to investigate the experimental quenching of M3 transition strength which is expected in the light of previous work. The shell-model predictions do not agree with the experimental data. In the case of the ²⁴Mg 5.236 MeV state the data are enhanced by a factor of approx.= 2 with respect to the shell-model prediction, whereas in the case of the ²⁸Si 10.376 MeV state the data are suppressed by a factor of approx.= 5. In the former case it is found that a small admixture of the 3₂⁺ state shell-model wave function into the 3₁⁺ state wave function gives good agreement with the data. The effects of this admixture on other observables are investigated. No similar mechanism is found to explain the ²⁸Si M3 transition. In view of the basic disagreement between the shell-model predictions and the experimental data, no conclusions about M3 quenching can be drawn. The validity of previous analyses using this technique is seriously questioned. (orig.)

[en] The parameter anti eta of muon decay has been measured in the radiative decay μ⁺ -> e⁺νsub(e) anti νsub(μ)γ of unpolarized positive muons. The result anti eta <= 0.083 (68% confidence) or anti eta = -0.03 +- 0.10 with p fixed at 3/4 yields an improvement of the previous value by more than a factor of two. An analysis of all data on muon decay that are presently available slightly improves the constraints on the weak coupling constants to: gsub(s) <= 0.29 gsub(v), gsub(P) <= 0.27 gsub(v), gsub(T) <= 0.23 gsub(V) and 0.92gsub(v) <= 1.27 gsub(v). (orig.)

[en] The time-dependent Hartree-Fock-Bogoliubov (TDHFB) method is applied to a system with a pairing interaction. A semiclassical prescription is used for the evaluation of the two-particle-transfer matrix elements. A comparison of matrix elements and excitation energies obtained in the TDHFB approach and the exact ones shows a very good agreement for large degeneracies. (orig.)

[en] A reconstruction of the scattering amplitudes for pp -> πd at 90⁰ and at 0⁰ c.m. is made from five sets of five polarization parameters measured at 447, 496, 515, 538, 578 MeV. These data allow a determination of the moduli and one relative phase of the three amplitudes at 90⁰ angle and two of the moduli at 0⁰. The deuteron tensor polarizations are also computed from these two reconstructions. (orig.)

[en] We discuss within the framework of an analytical model central collisions between large nuclei at an intermediate energy. The model assumes three stages: the ignition stage in which thermalized nucleons are created within the reaction volume; the expansion phase in which the hot nuclear matter expands and cools; and finally, the evaporation stage in which the system disintegrates through a surface evaporation. The model provides a qualitative insight into the connections between the main physical processes throughout the collision event. (orig.)

[en] Core polarization by valence neutrons is suggested as a possible mechanism for producing odd-even variation in the charge radii of isotopes. The nuclei considered have closed proton shells and neutrons in states with lowest seniority or generalized seniority. Simple expressions are derived for jsup(n) neutron configurations and various multipole terms of the pn interaction. The resulting expressions give a good fit to the radii of calcium isotopes and also of lead isotopes for which these expressions are only approximate. (orig.)