Coulomb excitation of pear-shaped nuclei

Peter Butler , Liam Gaffney , Pietro Spagnoletti , Joonas Konki , Marcus Scheck , John Smith , Kenzo Abrahams , Michael Bowry , Joakim Cederkäll , Timothy Chupp , Giacomo de Angelis , Hilde De Witte , Paul Garrett , Alina Goldkuhle , Corinna Henrich , Andres Illana , Karl Johnston , David Joss , James Keatings , Nicola Kelly , Michalina Komorowska , Thorsten Kröll , Miguel Lozano , Bondili Nara Singh , David O'Donnell , Joonas Ojala , Robert Page , Line Pedersen , Christopher Raison , Peter Reiter , Jose Alberto Rodriguez , Dawid Rosiak , Sebastian Rothe , Timur Shneidman , Burkhard Siebeck , Michael Seidlitz , Jacqueline Sinclair , Marek Stryjczyk , Piet van Duppen , Silvia Vinals , Ville Virtanen , Nigel Warr , Kasia Wrzosek-Lipska , Magda Zielinska (1)

1 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers

There is a large body of evidence that atomic nuclei can undergo octupole distortion and assume the shape of a pear. This phenomenon is important for measurements of electric-dipole moments of atoms, which would indicate CP violation and hence probe physics beyond the Standard Model of particle physics. Isotopes of both radon and radium have been identified as candidates for such measurements. Here, we have observed the low-lying quantum states in 224Rn and 226Rn by accelerating beams of these radioactive nuclei. We show that radon isotopes undergo octupole vibrations but do not possess static pear-shapes in their ground states. We conclude that radon atoms provide less favourable conditions for the enhancement of a measurable atomic electric-dipole moment.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

Peter Butler, Liam Gaffney, Pietro Spagnoletti, Joonas Konki, Marcus Scheck, et al.. Coulomb excitation of pear-shaped nuclei. 4th International Conference on Nuclear Structure and Dynamics, May 2019, Venice, Italy. pp.01007, ⟨10.1051/epjconf/201922301007⟩. ⟨hal-02441020⟩