Increase in width of the giant dipole resonance in hot nuclei: Shape change or collisional damping?

Journal Article · Mon May 08 04:00:00 EDT 1995 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.74.3748· OSTI ID:55265

Bracco, A; Camera, F; Mattiuzzi, M; Million, B; Pignanelli, M ^[1]; Gaardhoje, J J; Maj, A; Ramsoy, T; Tveter, T; Zelazny, Z ^[2]

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1. Dipartimento di Fisica, Universita di Milano and Istituto Nazionale di Fisica Nucleare Sezione di Milano, via Celoria 16, 20133 Milano (Italy)
2. The Niels Bohr Institute, Blagdamsvej 15-17, Copenhagen DK-2100 O (Denmark)

The strength function and the angular distribution of the high energy {gamma} rays emitted by the giant dipole resonance (GDR) in hot rotating{sup 109,110}Sn nuclei have been measured at temperature {ital T}=1.8 MeV and at four values of the angular momentum {ital I}. The GDR width is {approx}2 times larger than at {ital T}=0 and increases by {approx}20% as {ital I} goes from 40 to 54{h_bar}. The {ital a}{sub 2}({ital E}{sub {gamma}}) increases by a factor of {approx}2. Based on these two facts and on the comparison with theory we conclude that large deformations driven by {ital I} and combined with shape and orientation fluctuations are responsible for the measured increases. Collisional damping is constant and practically equal to the {ital T}=0 case.

• OSTI ID: 55265
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 19 Vol. 74; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ANGULAR DISTRIBUTION
ANGULAR MOMENTUM
DEFORMATION
DIPOLES
FLUCTUATIONS
GAMMA RADIATION
GIANT RESONANCE
HOT NUCLEI
SHAPE
STRENGTH FUNCTIONS
TIN 109
TIN 110
WIDTH