M. Gerbaux

Observation of the β-delayed γ-proton decay of (56)Zn and its impact on the Gamow-Teller strength evaluation.

We report the observation of a very exotic decay mode at the proton drip line, the β-delayed γ-proton decay, clearly seen in the β decay of the T_{z}=-2 nucleus ^{56}Zn. Three γ-proton sequences have been observed after the β decay. Here this decay mode, already observed in the sd shell, is seen for the first time in the fp shell. Both γ and proton decays have been taken into account in the estimation of the Fermi and Gamow-Teller strengths. Evidence for fragmentation of the Fermi strength due to strong isospin mixing is found.

β Decay of the exotic Tz=-2 nuclei Fe 48, Ni 52, and Zn 56

S. E. A. Orrigo, ∗ B. Rubio, Y. Fujita, 3 W. Gelletly, 4 J. Agramunt, A. Algora, 5 P. Ascher, B. Bilgier, B. Blank, L. Cáceres, R. B. Cakirli, E. Ganioğlu, M. Gerbaux, J. Giovinazzo, S. Grévy, O. Kamalou, H. C. Kozer, L. Kucuk, T. Kurtukian-Nieto, F. Molina, 9 L. Popescu, A. M. Rogers, G. Susoy, C. Stodel, T. Suzuki, A. Tamii, and J. C. Thomas Instituto de F́ısica Corpuscular, CSIC-Universidad de Valencia, E-46071 Valencia, Spain Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan Department of Physics, University of Surrey, Guildford GU2 7XH, Surrey, UK Inst. of Nuclear Research of the Hung. Acad. of Sciences, Debrecen, H-4026, Hungary Centre d’Etudes Nucléaires de Bordeaux Gradignan, CNRS/IN2P3 Université de Bordeaux, 33175 Gradignan Cedex, France Department of Physics, Istanbul University, Istanbul, 34134, Turkey Grand Accélérateur National d’Ions Lourds, CEA/DSM CNRS/IN2P3, BP 55027, F-14076 Caen, Cedex 5, France Comisión Chilena de Enerǵıa Nuclear, Casilla 188-D, Santiago, Chile SCK.CEN, Boeretang 200, 2400 Mol, Belgium Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA The results of a study of the beta decays of three proton-rich nuclei with Tz = -2, namely Fe, Ni and Zn, produced in an experiment carried out at GANIL, are reported. In all three cases we have extracted the half-lives and the total β-delayed proton emission branching ratios. We have measured the individual β-delayed protons and β-delayed γ rays and the branching ratios of the corresponding levels. Decay schemes have been determined for the three nuclei, and new energy levels are identified in the daughter nuclei. Competition between β-delayed protons and γ rays is observed in the de-excitation of the T = 2 Isobaric Analogue States in all three cases. Absolute Fermi and Gamow-Teller transition strengths have been determined. The mass excesses of the nuclei under study have been deduced. In addition, we discuss in detail the data analysis taking as a test case Zn, where the exotic β-delayed γ-proton decay has been observed.

Observation of the 2+ isomer in Co52

We report the first observation of the 2

βdecay of the exoticTz=−2nucleiFe48,Ni52, andZn56

^+

Beta decay of the exotic

isomer in

T_z

^{52}

= -2 nuclei

Co, produced in the

^{48}

\beta

Fe,

decay of the 0

^{52}

^+