Low lying electric dipole excitations in nuclei of the rare earth region

Conference · Wed Jan 01 00:00:00 EST 1992

OSTI ID:7174386

von Brentano, P; Zilges, A; Herzberg, R D ^[1]; Zamfir, N V ^[2]; Kneissl, U; Heil, R D; Pitz, H H ^[3]; Wesselborg, C ^[4]

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1. Koeln Univ. (Germany). Inst. fuer Kernphysik
2. Brookhaven National Lab., Upton, NY (United States)
3. Stuttgart Univ. (Germany). Inst. fuer Strahlenphysik
4. Giessen Univ. (Germany). Inst. fuer Kernphysik

From many experiments with low energy photon scattering on deformed rare earth nuclei we have obtained detailed information about the distribution of electric dipole strength below 4 MeV. Apart from some weaker transitions between 2 and 4 MeV we observed one, and sometimes two, very strong El-groundstate transitions around 1.5 MeV in all examined nuclei. They arise from the de-excitation of the bandheads of the (J[sup [pi]],K)=(l[sup [minus]],0) and (J[sup [pi]],K)=(l[sup [minus]],1) octupole vibrational bands. It is shown that the decay branching ratios and the absolute transition strengths of these states can be reproduced rather well with an improved T(El)-operator in the sdf-Interacting Boson Model. Another class of octupole states has been investigated in the region of the semimagic nucleus [sup 142]Nd. Here a quintuplet of collective excitations around 3.5 MeV is expected due to the coupling of the 3[minus]-octupole vibration with the 2+-quadrupole vibration. We performed photon scattering experiments on the odd A neighboring nucleus [sup 141]Pr and found first evidence for the existence of 3[sup [minus]][circle times]2+[circle times]particle-states.

• Research Organization: Brookhaven National Lab., Upton, NY (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 7174386
• Report Number(s): BNL-47889; CONF-920555-3; ON: DE93001441; TRN: 92-038080
• Resource Relation: Conference: 4. international spring seminar on nuclear physics: the building blocks of nuclear structure, Amalfi (Italy), 18-22 May 1992
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
RARE EARTH NUCLEI
E1-TRANSITIONS
BRANCHING RATIO
ELECTRIC DIPOLES
EVEN-EVEN NUCLEI
EXCITATION
HAMILTONIANS
INTERACTING BOSON MODEL
MATRIX ELEMENTS
NEODYMIUM 142
NUCLEAR DEFORMATION
NUCLEAR STRUCTURE
OCTUPOLES
PHOTON-NUCLEON INTERACTIONS
PRASEODYMIUM 141
QUADRUPOLES
SCATTERING
BASIC INTERACTIONS
DEFORMATION
DIPOLES
ELECTROMAGNETIC INTERACTIONS
ENERGY-LEVEL TRANSITIONS
INTERACTIONS
INTERMEDIATE MASS NUCLEI
ISOTOPES
MATHEMATICAL MODELS
MATHEMATICAL OPERATORS
MULTIPOLE TRANSITIONS
MULTIPOLES
NEODYMIUM ISOTOPES
NUCLEAR MODELS
NUCLEI
ODD-EVEN NUCLEI
PARTICLE INTERACTIONS
PHOTON-BARYON INTERACTIONS
PHOTON-HADRON INTERACTIONS
PRASEODYMIUM ISOTOPES
QUANTUM OPERATORS
RARE EARTH ISOTOPES
SHELL MODELS
STABLE ISOTOPES
663100* - Nuclear Structure- (1992-)