Static or dynamic pear shapes in radioactive nucleus 224Rn?

Abstract We report a comprehensive study on low-lying parity doublet states of 224 Rn by mixing both quadrupole- and octupole-shaped configurations in multireference covariant density functional theory, in which broken symmetries in configurations are restored using projection techniques. The low-lying energy spectrum is reasonably reproduced when the shape fluctuations in both the quadrupole and octupole shapes are considered. Electric octupole transition strength in 224 Rn is found to be $$B(E3; 3^-_1 \rightarrow 0^+_1)=43$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>B</mml:mi> <mml:mo>(</mml:mo> <mml:mi>E</mml:mi> <mml:mn>3</mml:mn> <mml:mo>;</mml:mo> <mml:msubsup> <mml:mn>3</mml:mn> <mml:mn>1</mml:mn> <mml:mo>-</mml:mo> </mml:msubsup> <mml:mo>→</mml:mo> <mml:msubsup> <mml:mn>0</mml:mn> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo> </mml:msubsup> <mml:mo>)</mml:mo> <mml:mo>=</mml:mo> <mml:mn>43</mml:mn> </mml:mrow> </mml:math> W.u., comparable to that in 224 Ra, whose data are 42(3) W.u.. Our results indicate that 224 Rn shares similar low-energy structure with 224 Ra despite the excitation energy of first $$3^-$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mn>3</mml:mn> <mml:mo>-</mml:mo> </mml:msup> </mml:math> state of the former nucleus is higher than that of the latter. This study suggests 224 Rn is a candidate for the search for permanent electric dipole moment.