Electric Quadrupole Transitions of Some Even-Even Neon Isotopes

Abstract

The reduced electric quadrupole transition strengths B(E2) from the first excited
2+ state to the ground 0+ state of some even-even Neon isotopes (18,20,22,24,26,28Ne)
have been calculated. All studied isotopes composed of 16O nucleus that is
considered as an inert core and the other valence particles considered to move over
the sd-shell model space within 1d5/2, 2s1/2 and 1d3/2 orbits.
The configuration mixing shell model with limiting number of orbitals in the
model space outside the inert core fail to reproduce the measured electric transition
strengths. Therefore, and for the purpose of enhancing the calculations, the
discarded space has been included through a microscopic theory which considers a
particle-hole excitations from the core orbits and from the model space orbits into
the higher orbits with 2 excitations. These effects are called core-polarization
effects.
The transition strengths have been calculated with effective nucleon charges
deduced from the core polarization calculations, and calculated with standard
effective nucleon charges eeff e
p  1.3 for the proton and e e eff
n  0.5 for neutron.
The calculations are based on sd-shell model space with USDB interactions.
The harmonic oscillator potential is used to generate the single particle matrix
elements, where the value of the size parameter b is adjusted to get the experimental
root mean square matter radii for each isotope.