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Title: Potential description of the positive- and negative-energy properties of the. cap alpha. + /sup 40/Ca system and. cap alpha. -cluster structure of /sup 44/Ti

Abstract

The ..cap alpha..-cluster structure of the /sup 44/Ti nucleus is investigated within a local potential model description, starting from the unique optical potential which describes elastic /sup 40/Ca(..cap alpha..,..cap alpha..) scattering on broad angular and energy ranges, and which has recently been shown to describe the broad oscillations seen in the low energy fusion excitation function as well. It is found that the various ..cap alpha..-cluster states group into quasirotational bands whose properties are not dissimilar to those of the well-understood /sup 20/Ne nucleus. The lowest lying band is composed of states of even parity with moderate cluster character at low spin; it agrees within a few MeV's in absolute energy with the /sup 44/Ti experimental ground state band, and the experimental intraband quadrupole transition probabilities are reproduced with good accuracy. The potential supports an excited positive parity band with strong cluster character, starting a few MeV's above the ..cap alpha..+ /sup 40/Ca threshold; the states of this band with spins ranging from 6 to 12 are responsible for the oscillations observed in the fusion excitation function. It supports, in addition, a negative parity band starting just above the threshold and composed of narrow states with intermediate cluster character; themore » latter has up to now no experimentally known counterpart. The states of higher lying bands are very broad and overlapping but they play an important role in enhancing the /sup 40/Ca(..cap alpha..,..cap alpha..) backward angle cross section. Our results are discussed in terms of the available experimental evidence and of the various, often conflicting theoretical interpretations which have been put forward to describe the /sup 44/Ti ..cap alpha..-cluster spectroscopy.« less

Authors:
; ;
Publication Date:
Research Org.:
Faculte des Sciences, Universite de l'Etat, B-7000 Mons, Belgium
OSTI Identifier:
5581137
Resource Type:
Journal Article
Journal Name:
Phys. Rev. C; (United States)
Additional Journal Information:
Journal Volume: 37:1
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ALPHA REACTIONS; HEAVY ION FUSION REACTIONS; CALCIUM 40 TARGET; TITANIUM 44; NUCLEAR STRUCTURE; CLUSTER MODEL; EXCITATION FUNCTIONS; OPTICAL MODELS; ROTATIONAL STATES; SHELL MODELS; BETA DECAY RADIOISOTOPES; CHARGED-PARTICLE REACTIONS; CROSS SECTIONS; ELECTRON CAPTURE RADIOISOTOPES; ENERGY LEVELS; EVEN-EVEN NUCLEI; EXCITED STATES; FUNCTIONS; INTERMEDIATE MASS NUCLEI; ISOTOPES; MATHEMATICAL MODELS; NUCLEAR MODELS; NUCLEAR REACTIONS; NUCLEI; RADIOISOTOPES; TARGETS; TITANIUM ISOTOPES; YEARS LIVING RADIOISOTOPES; 653001* - Nuclear Theory- Nuclear Structure, Moments, Spin, & Models

Citation Formats

Michel, F, Reidemeister, G, and Ohkubo, S. Potential description of the positive- and negative-energy properties of the. cap alpha. + /sup 40/Ca system and. cap alpha. -cluster structure of /sup 44/Ti. United States: N. p., 1988. Web. doi:10.1103/PhysRevC.37.292.
Michel, F, Reidemeister, G, & Ohkubo, S. Potential description of the positive- and negative-energy properties of the. cap alpha. + /sup 40/Ca system and. cap alpha. -cluster structure of /sup 44/Ti. United States. doi:10.1103/PhysRevC.37.292.
Michel, F, Reidemeister, G, and Ohkubo, S. Fri . "Potential description of the positive- and negative-energy properties of the. cap alpha. + /sup 40/Ca system and. cap alpha. -cluster structure of /sup 44/Ti". United States. doi:10.1103/PhysRevC.37.292.
@article{osti_5581137,
title = {Potential description of the positive- and negative-energy properties of the. cap alpha. + /sup 40/Ca system and. cap alpha. -cluster structure of /sup 44/Ti},
author = {Michel, F and Reidemeister, G and Ohkubo, S},
abstractNote = {The ..cap alpha..-cluster structure of the /sup 44/Ti nucleus is investigated within a local potential model description, starting from the unique optical potential which describes elastic /sup 40/Ca(..cap alpha..,..cap alpha..) scattering on broad angular and energy ranges, and which has recently been shown to describe the broad oscillations seen in the low energy fusion excitation function as well. It is found that the various ..cap alpha..-cluster states group into quasirotational bands whose properties are not dissimilar to those of the well-understood /sup 20/Ne nucleus. The lowest lying band is composed of states of even parity with moderate cluster character at low spin; it agrees within a few MeV's in absolute energy with the /sup 44/Ti experimental ground state band, and the experimental intraband quadrupole transition probabilities are reproduced with good accuracy. The potential supports an excited positive parity band with strong cluster character, starting a few MeV's above the ..cap alpha..+ /sup 40/Ca threshold; the states of this band with spins ranging from 6 to 12 are responsible for the oscillations observed in the fusion excitation function. It supports, in addition, a negative parity band starting just above the threshold and composed of narrow states with intermediate cluster character; the latter has up to now no experimentally known counterpart. The states of higher lying bands are very broad and overlapping but they play an important role in enhancing the /sup 40/Ca(..cap alpha..,..cap alpha..) backward angle cross section. Our results are discussed in terms of the available experimental evidence and of the various, often conflicting theoretical interpretations which have been put forward to describe the /sup 44/Ti ..cap alpha..-cluster spectroscopy.},
doi = {10.1103/PhysRevC.37.292},
journal = {Phys. Rev. C; (United States)},
number = ,
volume = 37:1,
place = {United States},
year = {1988},
month = {1}
}