26-30 June 2011
Centro Culturale Altinate, Padova, Italy
Europe/Rome timezone

Lifetime measurements on neutron-rich isotopes

30 Jun 2011, 12:18
17m
Sala Polivalente (Centro Culturale Altinate, Padova, Italy)

Sala Polivalente

Centro Culturale Altinate, Padova, Italy

Via Altinate 71 Padova Italy

Speaker

Víctor Modamio (LNL, INFN)

Description

In the region right below the neutron-rich Ni isotopes, there is an increase of collectivity produced mainly by the monopole part of the tensor interaction of the nuclear force: the interaction between f{7/2} protons and both f{5/2} neutrons (attractive) and g{9/2} neutrons (repulsive) weakens when the proton f{7/2} orbital is not fully filled, and therefore the gap between the neutron orbitals f{5/2} and the g{9/2} decreases. This mechanism will favor particle-hole excitations across N=40 subshell closure and therefore the g{9/2} orbital will play an important role in driving the nucleus towards deformation. An increase in collectivity in neutron-rich Cr isotopes towards N=40 is expected while observing the decrease in excitation energies of the first 2+ states as we increase the neutron number above the subshell closure at N=32. The cromium isotopes from N=28 up to N=38 undergo a shape transition from spherical (N=28, {52}Cr) to deformed in {60,62}Cr, with a 4{+}/2{+} typical of a γ-soft rotor. This kind of transition has been described within the framework of IBM and the critical-point where the phase transition is described by the E(5) symmetry (from spherical vibrator U(5) to a γ-soft rotor O(6)). The expected behaviour in the excitation energies (energy spectrum) of the E(5) symmetry was observed in the N=34 Cr isotope ({58}Cr). The shape evolution along the Cr isotopic chain will be studied in terms of measured B(E2) relative values of electromagnetic transitions in 58Cr and 60Cr. To this purpose, the nuclei of interest were populated as products of a multinucleon-transfer reaction with a 64Ni beam at an energy of 460 MeV, directed onto a {238}U target. Lifetimes of first excited states of 58,60Cr will be measured by using the Recoil Distance Doppler Shift method (RDDS) with the AGATA Demostrator-PRISMA setup. Preliminary results will be presented.

Primary authors

José Javier Valiente-Dobón (LNL, INFN) Víctor Modamio (LNL, INFN)

Co-authors

A. Algora (IFIC, Valencia, Spain) A. Dewald (IKP, Universitätt zu Köln, Köln, Germany) A. Gadea (IFIC Valencia, Valencia, Spain) A. Gottardo (INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova), Italy) A. Nannini (Dipartimento di Fisica, Università di Firenze and INFN, Firenze, Italy) A.B. Bürger (Department of Physics, University of Oslo, Oslo, Norway) A.M. Stefanini (INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova), Italy) B. Melon (Dipartimento di Fisica, Università di Firenze and INFN, Firenze, Italy) C. Michelagnoli (Dipartimento di Fisica, Università di Padova and INFN, Padova, Italy) C. Ur (Dipartimento di Fisica, Università di Padova and INFN) D. Bazzaco (Dipartimento di Fisica, Università di Padova and INFN, Padova, Italy) D. Mengoni (Dipartimento di Fisica, Università di Padova and INFN, Padova, Italy) D. Montanari (INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova), Italy) D.R. Napoli (INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova), Italy) E. Farnea (Dipartimento di Fisica, Università di Padova and INFN, Padova, Italy) E. Fioretto (INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova), Italy) E. Sahin (INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova), Italy) F. Recchia (Dipartimento di Fisica, Università di Padova and INFN, Padova, Italy) F. Scarlassara (Dipartimento di Fisica, Università di Padova and INFN, Padova, Italy) G. Montagnoli (Dipartimento di Fisica, Università di Padova and INFN, Padova, Italy) G. de Angelis (INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova), Italy) K. Geibel (IKP, Universitätt zu Köln, Köln, Germany) L. Corradi (INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova), Italy) M. Hackstein (IKP, Universitätt zu Köln, Köln, Germany) M.N. Erduran (Department of Physics, Istanbul University, Istanbul, Turkey) O. Möller (Technische Universität Darmstadt, Darmstadt, Germany) P. Reiter (IKP, Universitätt zu Köln, Köln, Germany) P.A. Söderström (Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden) R. Depalo (Dipartimento di Fisica, Università di Padova and INFN, Padova, Italy) R. Kempley (Department of Physics, University of Surrey, Guildford, U.K.) R. Menegazzo (Dipartimento di Fisica, Università di Padova and INFN, Padova, Italy) S. Lenzi (Department of Physics, University of Surrey, Guildford, U.K.) S. Lunardi (Dipartimento di Fisica, Università di Padova and INFN, Padova, Italy) S. Szilner (Ruder Boskovic Institute, Zagreb, Croatia) T. Hüyük (IFIC Valencia, Valencia, Spain) W. Rother (IKP, Universitätt zu Köln, Köln, Germany)

Presentation Materials