Electrically charged compact stars

We review here the classical argument used to justify the electrical neutrality of stars and show that if the pressure and density of the matter and gravitational field inside the star are large, then a charge and a strong electric field can be present. For a neutron star with high pressure (~ 10^{33} to 10^{35} dynes /cm^2) and strong gravitational field (~ 10^{14} cm/s^2), these conditions are satisfied. The hydrostatic equation which arises from general relativity, is modified considerably to meet the requirements of the inclusion of the charge. In order to see any appreciable effect on the phenomenology of the neutron stars, the charge and the electrical fields have to be huge (~ 10^{21} Volts/cm). These stars are not however stable from the viewpoint that each charged particle is unbound to the uncharged particles, and thus the system collapses one step further to a charged black holeComment: Proceedings of 10th Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Gravitation and Relativistic Field Theories (MG X MMIII), Rio de Janeiro, Brazil, 20-26 Jul 200

Observation of mean-spin barrier bump in sub-barrier fusion of sup 28 Si with sup 154 Sm

We have measured the fusion excitation function and gamma-ray multiplicities, M{sub gamma}, for the {sup 28}Si + {sup 154}Sm system. We have also measured M{sub {gamma}} for the {sup 16}O + {sup 166} Er system that leads to the same compound nucleus, {sup 182}Os. This is used to calibrate the connection between M{sub {gamma}} and the first moment of the spin distribution of the compound nucleus, {l angle}{ell}{r angle}. We find that the deduced {l angle}{ell}{r angle} in {sup 28}Si + {sup 154}Sm agrees reasonably well with theoretical expectations, and in particular exhibits the barrier bump expected when another degree of freedom is strongly coupled to the relative motion. 17 refs., 2 figs