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

• Published in: Physical review letters 1990-12, Vol.65:26
• Main Authors: Gil, S., Abriola, D., DiGregorio, D.E., di Tada, M., Elgue, M., Etchegoyen, A., Etchegoyen, M.C., Fernandez Niello, J., Ferrero, A.M.J., Macchiavelli, A.O., Pacheco, A.J., Testoni, J.E., Silveira Gomes, P., Vanin, V.R., Charlop, A., Garcriaaa, A., Kailas, S., Luke, S.J., Renshaw, E., Vandenbosch, R.
• Format: Article
• Language: English
• Subjects: 651420 - Nuclear Properties & Reactions, A=20-38, Experimental; 651820 - Nuclear Properties & Reactions, A=150-189, Experimental; ANGULAR MOMENTUM; CALIBRATION; CHARGED-PARTICLE REACTIONS; CROSS SECTIONS; DATA; ELEMENTARY PARTICLES; ELEMENTS; ENERGY RANGE; EUROPIUM; EXPERIMENTAL DATA; HEAVY ION REACTIONS; INFORMATION; MASSLESS PARTICLES; METALS; MEV RANGE; MEV RANGE 10-100; NUCLEAR PHYSICS AND RADIATION PHYSICS; NUCLEAR REACTIONS; NUMERICAL DATA; OXYGEN 16 REACTIONS; PARTICLE PROPERTIES; PHOTONS; RARE EARTHS; SAMARIUM 154 TARGET; SILICON 28 REACTIONS; SPIN; TARGETS
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.65.3100

We have measured the fusion excitation function and {gamma}-ray multiplicities {ital M}{sub {gamma}} for the {sup 28}Si+{sup 154}Sm system. We have also measured {ital M}{sub {gamma}} for the {sup 16}O+{sup 166}Er system that leads to the same compound nucleus, {sup 182}Os, as a calibration of the connection between {ital M}{sub {gamma}} and the first moment of the spin distribution, {l angle}{ital l}{r angle}. We find that the deduced {l angle}{ital l}{r angle} for {sup 28}Si+{sup 154}Sm agrees reasonably well with theoretical calculations, and in particular its energy dependence exhibits the barrier bump expected when a shape degree of freedom is strongly coupled to the relative motion.