2 research outputs found
Energy averages and fluctuations in the decay out of superdeformed bands
We derive analytic formulae for the energy average (including the energy
average of the fluctuation contribution) and variance of the intraband decay
intensity of a superdeformed band. Our results may be expressed in terms of
three dimensionless variables: , ,
and . Here is
the spreading width for the mixing of a superdeformed (SD) state with the
normally deformed (ND) states whose spin is the same as 's. The
have mean level spacing and mean electromagnetic decay width
whilst has electromagnetic decay width .
The average decay intensity may be expressed solely in terms of the variables
and or, analogously to statistical
nuclear reaction theory, in terms of the transmission coefficients and
describing transmission from the to the SD band via and
to lower ND states.
The variance of the decay intensity, in analogy with Ericson's theory of
cross section fluctuations depends on an additional variable, the correlation
length
\Gamma_N/(\Gamma_S+\Gamma^{\downarrow})=\frac{d}{2\pi}T_N/(\Gamma_S+\Gamma^{\d
ownarrow}). This suggests that analysis of an experimentally obtained variance
could yield the mean level spacing as does analysis of the cross section
autocorrelation function in compound nuclear reactions.
We compare our results with those of Gu and Weidenm\"uller.Comment: revtex4, 14 pages, 4 figures, to appear in Physical Review
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Theory of Rotational Population Patterns in Heavy-Ion Transfer Reactions: Even-Even Thorium Nuclei
A Hamiltonian matrix diagonalization (HMD) method is applied to calculate the lowest several bands in {sup 230,232,234}Th. Neutron pair transfer strength distributions are calculated and compared between HMD and cranked Hartree-Fock-Bogoliubov plus Random Phase Approximation (CHFB+RPA). Sudden-approximation methods are applied to estimate pair transfer population patterns in {sup 206}Pb + {sup 232}Th reactions. Band-crossing, pairing, and spin alignment properties are also discussed