Showing papers in "Nuclear Physics in 1961"

TL;DR: In this paper, the weak and electromagnetic interactions of leptons are examined under the hypothesis that the weak interactions are mediated by vector bosons, and it is shown that the simplest partially-symmetric model reproducing the observed electromagnetic and weak interactions requires the existence of at least four vector-boson fields (including the photon).

TL;DR: In this article, a representation for the baryons and bosons based on the Lie algebra of the 3-dimensional traceless matrices is suggested, which enables us to generate the strong interactions from a gauge invariance principle, involving 8 vector bosons.

TL;DR: In this article, a new formulation of the general theory of nuclear reactions is proposed, on the basis of a definition of the resonant states as decaying states corresponding to complex eigenvalues of the total energy of the compound system.

TL;DR: In this paper, it was shown that it is always possible to choose an independent particle wave function which makes all collective modes stable in the random phase approximation of the Green's function.

TL;DR: The mechanism of the particle-hole interaction in producing the giant dipole resonance in nuclei is discussed in detail in this paper, where calculations in j - j coupling were carried out with zero-range forces for the nuclei O/sup 16/ and Ca/sup 40.

TL;DR: In this paper, it was pointed out that on the basis of Chisholm's theorem, most of the ordinary equivalence theorems in field theories can be obtained by rather trivial changes of variables in the Lagrangians.

TL;DR: In this article, the distribution function of the level spacings for a random matrix in the limit of large dimensions is expressed by means of a rapidly converging infinite product which has been used for a numerical calculation.

TL;DR: In this paper, the energy-level displacements for atomic states of two oppositel-charged nuclear particles due to their strong interactions are related to the parameters of the effective range approximation for the low-energy scattering of these two particles.

TL;DR: When a single proton is added to, or a single neutron removed from, a definite shell model orbit in a target nucleus, the total strength can in general be divided into two parts, each part being characterized by a definite value of the isobaric spin T.

TL;DR: In this paper, new terms were proposed for the atomic mass law, which incorporated effects of nuclear deformation and shell structure including interference effects between unfilled neutron and proton shells, and Coulomb terms were fixed by recent radii determinations in electron scattering.

TL;DR: In this paper, it was shown that any local or almost local change of variables in quantum field theories which leaves the free field part of the Lagrangian unchanged does not alter the S-matrix.

TL;DR: In this paper, the eigenvalues of these 3N integrals of motion were obtained by applying the corresponding operators to the reduced canonical wave function defined in a previous paper, which gave a basis for all the irreducible representations of the three dimensional unitary unimodular group.

TL;DR: In this article, direct electric dipole capture γ-ray transitions are calculated for a number of cases of charged particle capture in nuclei and it is found that when the γray energy is sufficiently low, below about 2 MeV, the capture matrix element is determined by regions external to the usual nuclear radius.

TL;DR: Using the generalized method of canonical transformation an expression for the nuclear moment of inertia was found with allowances for nucleon pairing as discussed by the authors, which coincides with that obtained earlier by A. Migdal by the Green's function method.

TL;DR: In this article, the influence of the pairing correlations on the ground-state equilibrium deformation of nuclei has been investigated and the strength of the quadrupole interaction, needed to account for the empirical electric quadrupoles moments, is compared with the values used in other investigations.

TL;DR: In this article, the relation between these classifications for the various nucleon numbers is studied and is found to be governed by another symplectic group, the transformations of which in general change the nucleon number.

TL;DR: In this paper, the particle-hole interaction is discussed as the mechanism for producing vibrational states in nuclei, and the procedure is first illustrated by means of a schematic model, from which it is shown that the usual type of shell-model caculation must be extended to include correlations in the ground state of the nucleus before it can be applied to the calculation of vibrational state.

TL;DR: In this paper, the 14 MeV differential (n, p) cross sections of about 40 nuclei have been measured at 120° to the incident neutrons using a photographic plate method.

TL;DR: In this paper, a modified form of the curve drawn by Newton for the value of the single particle level density parameter a is found to be in accord with the data and attention is drawn to the effect of restriction of the allowed angular momentum of the emitted particles on the value found for the temperature in an evaporative process.

TL;DR: In this paper, the quasi-particle and the boson approximation are used in the study of the first 0+ excited state of the pairing force: a special case is chosen for its simplicity, which allows us to study quantitatively the validity of these approximations.

TL;DR: In this paper, it was shown that the non-vanishing of the current-charge density commutator at equal times is required by and is compatible with the continuity equation.

TL;DR: In this article, the problem of detecting high-energy cosmic neutrinos in underground experiments is discussed, and various kindred problems of high energy neutrino physics are discussed, viz. (1) the magnitude of weak-interaction cut-off momentum, (2) muon and electron neutrions and (3) intermediate boson.

TL;DR: In this article, the α-α scattering phase shifts were calculated with two nucleon forces which describe the low energy two-nucleon scattering data, and the obtained results were discussed.

TL;DR: In this article, the positions and widths of the states produced by weakly coupling a 2s- or Id-neutron to a core consisting of the ground or first excited state of C12 are mixed by means of a two-body central interaction and a one-body spin-orbit interaction of the type normally used in intermediate-coupling calculations, to provide the low-lying positive-parity eigenstates of C13.

TL;DR: In this paper, the solutions of the set of equations for the rotation-vibrational spectrum of non-spherical nuclei are investigated, γ vibrations being taken into account in the equations.

TL;DR: In this paper, a neutron time-of-flight spectrometer has been used to measure the total cross-sections of hydrogen, carbon, aluminium, copper, cadmium, lead and uranium at 64 energies in the range 15 to 120 MeV.

TL;DR: In this article, total cross-sections for (n, 2n) reactions have been measured at 14.8 MeV neutron energy for more than twenty cases by the activation method and the observed values have been compared with those calculated on the statistical model using level density formulae of Lang and Le Couteur.

TL;DR: In this article, the convergence problem arising from the combination of the forward dispersion relation with the unitarity condition on the physical cut is solved via a conformal transformation via a two-dimensional spectral representation of Mandelstam.

TL;DR: In this article, the reduced electric quadrupole transition probabilities and the excitation energies of the accessible low lying states in the stable isotopes of Hf and W (except the rare isotope W180) have been measured by Coulomb excitation.

TL;DR: In this article, it was found that the interaction of levels of opposite parity makes the nuclei in certain regions very soft to octupole deformation and the potential surface of the fission barrier would therefore possess two asymmetric valleys.