ON THE TRANSITIONS BETWEEN SENIORITY-FOUR AND SENIORITY-TWO STATES COMPARED TO THE TWO-PHONON-ONE-PHONON TRANSITIONS.
Journal Article
·
· Nucl. Phys., A114: 161-83 (1968).
- Research Organization:
- CNRS, Orsay, France
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-22-035381
- OSTI ID:
- 4501495
- Journal Information:
- Nucl. Phys., A114: 161-83 (1968)., Other Information: Orig. Receipt Date: 31-DEC-68
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
Similar Records
Most theoretical approaches used in nuclear astrophysics to model the nucleosynthesis of heavy elements incorporate the so-called statistical model in order to describe the excitation and decay properties of atomic nuclei. One of the basic assumptions of this model is the validity of the Brink–Axel hypothesis and the related concept of so-called photon strength functions to describe γ-ray transition probabilities. We present a novel experimental approach that allows for the first time to experimentally determine the photon strength function simultaneously in two independent ways by a unique combination of quasi-monochromatic photon beams and a newly implemented γ–γ coincidence setup. This technique does not assume a priori the validity of the Brink–Axel hypothesis and sets a benchmark in terms of the detection sensitivity for measuring decay properties of photo-excited states below the neutron separation energy. The data for the spherical off-shell nucleus 128Te were obtained for γ-ray beam-energy settings between 3 MeV and 9 MeV in steps of 130 keV for the lower beam energies and in steps of up to 280 keV for the highest beam settings. We present a quantitative analysis on the consistency of the derived photon strength function with the Brink–Axel hypothesis. The data clearly demonstrate a discrepancy of up to a factor of two between the photon strength functions extracted from the photoabsorption and photon emission process, respectively. In addition, we observe that the photon strength functions are not independent of the excitation energy, as usually assumed. Thus, we conclude, that the Brink–Axel hypothesis is not strictly fulfilled in the excitation-energy region below the neutron separation threshold (Sn = 8.78 MeV) for the studied case of 128Te.
EIGENSTATES OF THE J = 0, T = 1, CHARGE-INDEPENDENT PAIRING HAMILTONIAN. II. SENIORITY-ONE AND -TWO STATES.
FOUR-QUASIPARTICLE EXCITATIONS AND TWO-PHONON VIBRATIONAL STATES IN SPHERICAL NUCLEI: EVEN-PARITY STATES OF EVEN TIN ISOTOPES.
Journal Article
·
Tue Jan 01 00:00:00 EST 2019
· Physics Letters B
·
OSTI ID:4501495
+10 more
EIGENSTATES OF THE J = 0, T = 1, CHARGE-INDEPENDENT PAIRING HAMILTONIAN. II. SENIORITY-ONE AND -TWO STATES.
Journal Article
·
Sun Jan 01 00:00:00 EST 1967
· Phys. Rev., 154: 1007-22(Feb. 20, 1967).
·
OSTI ID:4501495
FOUR-QUASIPARTICLE EXCITATIONS AND TWO-PHONON VIBRATIONAL STATES IN SPHERICAL NUCLEI: EVEN-PARITY STATES OF EVEN TIN ISOTOPES.
Journal Article
·
Sun Jan 01 00:00:00 EST 1967
· Phys. Rev., 153: 1138-47(Jan. 20, 1967).
·
OSTI ID:4501495
+1 more
Related Subjects
N36610* -Physics (Nuclear)-Nuclear Theory-Nuclear Structure
ENERGY LEVELS
NUCLEAR MODELS
NUCLEAR STRUCTURE
NUCLEI
PHONONS
QUANTUM MECHANICS
SENIORITY NUMBER
NUCLEAR STRUCTURE/transitions between seniority-4 and seniority-2 states compared to 2-phonon-1-phonon transitions
QUANTUM MECHANICS/ transitions between seniority-4 and seniority-2 states compared to 2-phonon-1- phonon transitions
ENERGY LEVELS
NUCLEAR MODELS
NUCLEAR STRUCTURE
NUCLEI
PHONONS
QUANTUM MECHANICS
SENIORITY NUMBER
NUCLEAR STRUCTURE/transitions between seniority-4 and seniority-2 states compared to 2-phonon-1-phonon transitions
QUANTUM MECHANICS/ transitions between seniority-4 and seniority-2 states compared to 2-phonon-1- phonon transitions