Engineering topics

Brown, B Alex

Publications and source records attributed to Brown, B Alex.

4 records

DOE OSTI2011

Effects of isospin mixing in the A=32 quintet

For the A=32, T=2 quintet we provide a unified theoretical description for three related aspects of isospin mixing: the necessity of more than three terms in the isobaric mass multiplet equation, isospin-forbidden proton decay in {sup 32}Cl, and a correction to the allowed Fermi {beta}{sup +} decay of {sup 32}Ar. We demonstrate that all three effects observed in experiment can be traced to a common origin related to isospin mixing of the T=2 states with T=1 states.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2011

Properties of {sup 26}Mg and {sup 26}Si in the sd shell model and the determination of the {sup 25}Al(p,{gamma}){sup 26}Si reaction rate

We present theoretical results for the {sup 25}Al(p,{gamma}){sup 26}Si resonance-capture rate. The isobaric mass multiplet equation is used to determine the energies and J{sup {pi}} values of states in {sup 26}Si based upon those observed in {sup 26}Mg and {sup 26}Al together with sd shell calculations for the c coefficients. Three Hamiltonians for the sd shell, USD, USDA and USDB, are used to estimate the theoretical uncertainties in the {gamma}-decay and proton-decay widths that go into the resonance-capture rate.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2011

E6 Gamma Decay

Rare electric hexacontatetrapole (E6) transitions are studied in the full (f{sub 7/2},f{sub 5/2},p{sub 3/2},p{sub 1/2}) shell-model basis. Comparison of theory to the results from the gamma decay in {sup 53}Fe and from inelastic electron scattering on {sup 52}Cr provides unique and interesting tests of the valence wavefunctions, the models used for energy density functionals and into the origin of effective charge.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2011

Structure of unstable nuclei around N = 28 described by a shell model with the monopole-based universal interaction

The structure of exotic nuclei around N = 28 is investigated in the sd-pf shell-model space using a new effective interaction. The cross-shell part of the interaction is provided by the monopole-based universal interaction which has been successful in accounting for single-particle evolution in several mass regions. Focusing on the nuclear structure that is sensitive to the shell evolution, we show successful results for the proton-hole states in K isotopes and large deformation in {sup 42}Si. The results demonstrate that the present scheme may be a promising way for constructing an effective interaction for other mass regions.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗