Quadrupole collectivity in $^{42}\mathrm{Ca}$ from low-energy Coulomb excitation with AGATA

K. Hadyńska-Klȩk , P.J. Napiorkowski , M. Zielińska (1) , J. Srebrny , A. Maj , F. Azaiez (2) , J.J. Valiente Dobón , M. Kicińska-Habior , F. Nowacki (3) , H. Naïdja (3) , B. Bounthong (3) , T.R. Rodríguez , G. de Angelis , T. Abraham , G. Anil Kumar , D. Bazzacco , M. Bellato , D. Bortolato , P. Bednarczyk , G. Benzoni , L. Berti , B. Birkenbach , B. Bruyneel , S. Brambilla , F. Camera , J. Chavas (1) , B. Cederwall , L. Charles (3) , M. Ciemała , P. Cocconi , P. Coleman-Smith , A. Colombo , A. Corsi , F.C.L. Crespi , D.M. Cullen , A. Czermak , P. Désesquelles (4, 5) , D.T. Doherty (1) , B. Dulny , J. Eberth , E. Farnea , B. Fornal , S. Franchoo (2) , A. Gadea , A. Giaz , A. Gottardo , X. Grave (2) , J. Grȩbosz , A. Görgen , M. Gulmini , T. Habermann , H. Hess , R. Isocrate , J. Iwanicki , G. Jaworski , D.S. Judson , A. Jungclaus , N. Karkour (5) , M. Kmiecik , D. Karpiński , M. Kisieliński , N. Kondratyev , A. Korichi (5) , M. Komorowska , M. Kowalczyk , W. Korten (1) , M. Krzysiek , G. Lehaut (6) , S. Leoni , J. Ljungvall (5) , A. Lopez-Martens (5) , S. Lunardi , G. Maron , K. Mazurek , R. Menegazzo , D. Mengoni , E. Merchán , W. Mȩczyński , C. Michelagnoli , B. Million , S. Myalski , D.R. Napoli , M. Niikura (2) , A. Obertelli (1) , S.F. Özmen , M. Palacz , L. Próchniak , A. Pullia , B. Quintana , G. Rampazzo , F. Recchia , N. Redon (6) , P. Reiter , D. Rosso , K. Rusek , E. Sahin , M.D. Salsac (1) , P.A. Söderström , I. Stefan (2) , O. Stézowski (6) , J. Styczeń , Ch. Theisen (1) , N. Toniolo , C.A. Ur , R. Wadsworth , B. Wasilewska , A. Wiens , J.L. Wood , K. Wrzosek-Lipska , M. Ziȩbliński

1 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
2 IPNO - Institut de Physique Nucléaire d'Orsay
3 IPHC - Institut Pluridisciplinaire Hubert Curien
4 UP11 - Université Paris-Sud - Paris 11
5 CSNSM - Centre de Sciences Nucléaires et de Sciences de la Matière
6 IPNL - Institut de Physique Nucléaire de Lyon

A Coulomb-excitation experiment to study electromagnetic properties of Ca42 was performed using a 170-MeV calcium beam from the TANDEM XPU facility at INFN Laboratori Nazionali di Legnaro. γ rays from excited states in Ca42 were measured with the AGATA spectrometer. The magnitudes and relative signs of ten E2 matrix elements coupling six low-lying states in Ca42, including the diagonal E2 matrix elements of 21+ and 22+ states, were determined using the least-squares code gosia. The obtained set of reduced E2 matrix elements was analyzed using the quadrupole sum rule method and yielded overall quadrupole deformation for 01,2+ and 21,2+ states, as well as triaxiality for 01,2+ states, establishing the coexistence of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca42. The experimental results were compared with the state-of-the-art large-scale shell-model and beyond-mean-field calculations, which reproduce well the general picture of shape coexistence in Ca42.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

K. Hadyńska-Klȩk, P.J. Napiorkowski, M. Zielińska, J. Srebrny, A. Maj, et al.. Quadrupole collectivity in $^{42}\mathrm{Ca}$ from low-energy Coulomb excitation with AGATA. Phys.Rev.C, 2018, 97 (2), pp.024326. ⟨10.1103/PhysRevC.97.024326⟩. ⟨hal-01730128⟩