20265396
E3 transition probabilities in the platinum, mercury, and lead isotopes.
Spectroscopical properties of the platinum, mercury, and lead isotopes are studied within the Hartree-Fock plus BCS framework with the finite range density-dependent Gogny force. These properties are also studied beyond mean-field theory by combining the use of generator-coordinate-method-like wave functions with the angular momentum projection technique as to generate many-body correlated wave functions that are at the same time eigenstates of the angular momentum operator. We apply this formalism to the calculation of reduced transition probabilities {ital B}({ital E}3) from the lowest-lying octupole collective state to the ground state of several isotopes of the platinum, mercury, and lead nuclei whose experimental {ital B}({ital E}3) values present a peculiar behavior. The projected calculations show a large improvement over the unprojected ones when compared with the experimental data. The unprojected calculations are unable to predict any structure in the {ital B}({ital E}3). {copyright} {ital 1996 The American Physical Society.}
191289028
Charm and Beauty Production from Fermilab Experiment 789
16739726
Spacings of quarkonium levels with the same principal quantum number.
The spacings between bound-state levels of the Schr{umlt o}dinger equation with the same principal quantum number {ital N} but orbital angular momenta {ital l} differing by unity are found to be nearly equal for a wide range of power potentials {ital V}={lambda}{ital r}{sup {nu}}, with {ital E}{sub {ital Nl}}{approx_equal}{ital F}({nu},{ital N}){minus}{ital G}({nu},{ital N}){ital l}. Semiclassical approximations are in accord with this behavior. The result is applied to estimates of masses for quarkonium levels which have not yet been observed, including the 2{ital P} {ital c{bar c}} states and the 1{ital D} {ital b{bar b}} states. {copyright} {ital 1996 The American Physical Society.}
41996012
Stability of systems of three arbitrary charges: General properties.
The stability of systems consisting of a negative charge {minus}{ital q}{sub 1} and two positive charges {ital q}{sub 2} and {ital q}{sub 3} is discussed as a function of the values of the charges {ital q}{sub {ital i}} and of the constituent masses {ital m}{sub {ital i}}. We give general results and list some open questions of interest, which hopefully will stimulate further investigations.
28053143
Renormalizable top-quark condensate models.
Recently it has been suggested that electroweak symmetry is broken by a top-quark vacuum condensate. We discuss the prospects for making a renormalizable version of this ``top bootstrap'' scenario using a strongly coupled spontaneously broken gauge interaction. Several specific models are considered. We argue that these models are somewhat similar to the extended technicolor models, but with a ``technicolor'' force which is broken, providing the mass-generation mechanism for the top quark. From this point of view, the top quark plays the role of a techniquark.
12348580
Cosmological perturbations and classical change of signature.
Cosmological perturbations on a manifold admitting signature change are studied. The background solution consists in a Friedmann-Lemaitre-Robertson- Walker (FLRW) Universe filled by a constant scalar field playing the role of a cosmological constant. It is shown that no regular solution exist satisfying the junction conditions at the surface of change. The comparison with similar studies in quantum cosmology is made.
28650811
Crossing intrinsic depolarizing resonances by varying a partial Siberian snake.
We recently forced a 140 MeV polarized proton beam to cross intrinsic depolarizing resonances by varying a partial Siberian snake{close_quote}s strength for different values of the vertical and horizontal betatron tunes {nu}{sub {ital y}} and {nu}{sub {ital x}}. A weak second-order intrinsic resonance was observed in the {nu}{sub {ital x}} sweep; moreover, an unexpected partial spin flip was found in the {nu}{sub {ital y}} sweep. We also varied the snake ramp time to identify the {nu}{sub {ital y}} and {nu}{sub {ital x}} regions where the resonance crossings occurred during the snake variation; in these crossings the polarization partially deviated from Froissart-Stora behavior. {copyright} {ital 1996 The American Physical Society.}