Direct experimental evidence for a multiparticle-hole ground state configuration of deformed Mg-33

Publication Type
Journal Article
Year of Publication
Datta, U.
Rahaman, A.
Aumann, T.
Beceiro-Novo, S.
Boretzky, K.
Caesar, C.
Carlson, B. V.
Catford, W. N.
Chakraborty, S.
Chartier, M.
Cortina-Gil, D.
de Angelis, G.
Fernandez, P. D.
Emling, H.
Ershova, O.
Fraile, L. M.
Geissel, H.
Gonzalez-Diaz, D.
Jonson, B.
Johansson, H.
Kalantar-Nayestanaki, N.
Krucken, R.
Kurcewicz, J.
Langer, C.
Le Bleis, T.
Leifels, Y.
Marganiec, J.
Munzenberg, G.
Najafi, M. A.
Nilsson, T.
Nociforo, C.
Panin, V.
Paschalis, S.
Plag, R.
Reifarth, R.
Ricciardi, V.
Rossi, D.
Scheit, H.
Scheidenberger, C.
Simon, H.
Taylor, J. T.
Togano, Y.
Typel, S.
Volkov, V.
Wagner, A.
Wamers, F.
Weick, H.
Weigand, M.
Winfield, J. S.
Yakorev, D.
Zoric, M.
Name of Publication
Physical Review C
Date Published
Short Title
Direct experimental evidence for a multiparticle-hole ground state configuration of deformed Mg-33
Accession Number
ISBN Number

The first direct experimental evidence of a multiparticle-hole ground state configuration of the neutron-rich Mg-33 isotope has been obtained via intermediate energy (400 A MeV) Coulomb dissociation measurement. The major part similar to(70 +/- 13)% of the cross section is observed to populate the excited states of Mg-32 after the Coulomb breakup of Mg-33. The shapes of the differential Coulomb dissociation cross sections in coincidence with different core excited states favor that the valence neutron occupies both the s(1/2) and p(3/2) orbitals. These experimental findings suggest a significant reduction and merging of sd-pf shell gaps at N similar to 20 and 28. The ground state configuration of Mg-33 is predominantly a combination of Mg-32(3.0,3.5MeV; 2(-), 1(-)) circle times nu(s1/2), Mg-32(2.5MeV; 2(+)) circle times nu(p3/2), and Mg-32(0; 0(+)) circle times nu(p3/2). The experimentally obtained quantitative spectroscopic information for the valence neutron occupation of the s and p orbitals, coupled with different core states, is in agreement with Monte Carlo shell model (MCSM) calculation using 3 MeV as the shell gap at N = 20.