Broken reflection symmetry (and isospin dependence of enhanced E1 transitions) in [sup 114]Xe

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7042075

Rugari, S L

The authors have carried out a search for broken reflection symmetry in the exotic nucleus [sup 114]Xe. Evidence for broken reflection symmetry has been discussed in terms alpha clustering and octupole deformation. The alpha clustering model makes global predictions of the relative strengths of enhanced electric dipole (E1) transitions characteristic of broken reflection symmetry, and predicts a dependence on isospin divided by nuclear mass (N-Z)[sup 2]/A[sup 2] of the reduced transition probability, B(E1), where A is the nuclear mass number and N and Z are the neutron and proton number. In [sup 114]Xe (N-Z)[sup 2]/A[sup 2] = .0028, allowing for a test of the prediction. The octupole model description is less straightforward. Two terms contributing to the calculation of reduced transition strengths are based on the collective liquid drop model of nuclei and have a global dependence on A[sup 2]Z[sup 2]. A third term depends explicitly on the shell model description of the valence nucleons and can be large enough to remove this global dependence. The nucleus [sup 114]Xe was produced in the heavy ion fusion evaporation reaction [sup 60]Ni([sup 58]Ni,2p2n)[sup 114]Xe in two separate measurements at Daresbury Lab. and at Yale Univ. The nucleus was identified by means of a recoil mass spectrometer in the first reaction and by detection of evaporated neutrons in the second. Gamma ray spectra were collected in coincidence with these triggers. The authors have constructed the level spectrum of [sup 114]Xe from these measurements up to spin and parity 10[sup +] and excitation energy of about 3 MeV. The spectrum shows evidence of broken reflection symmetry in structure and in extracted B(E1) transition strengths. The extracted reduced E1 transition strength has been found to scale qualitatively according to (N-Z)[sup 2]/A[sup 2], as predicted by the alpha cluster model.

• Research Organization: Yale Univ., New Haven, CT (United States)
• OSTI ID: 7042075
• Country of Publication: United States
• Language: English

Related Subjects

663220* -- Electromagnetic Transitions-- (1992-)
663560 -- Nuclear Mass Ranges-- A=90-149-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
E1-TRANSITIONS
ELECTRON CAPTURE RADIOISOTOPES
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
INTERMEDIATE MASS NUCLEI
ISOSPIN
ISOTOPES
MATHEMATICAL MODELS
MULTIPOLE TRANSITIONS
MULTIPOLES
NUCLEAR MODELS
NUCLEI
OCTUPOLES
PARTICLE PROPERTIES
RADIOISOTOPES
REFLECTION
SECONDS LIVING RADIOISOTOPES
SHELL MODELS
SYMMETRY BREAKING
XENON 114
XENON ISOTOPES