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Ana Montaner Pizá . Instituto de Física Corpuscular IFIC, Valencia, Spain. . Isospin Mixing And In-beam Study Of 56 C o Non- yrast States At MLL/ Miniball . Motivation And First Glance On The Results Of The Experiment. MINIBALL Workshop . 24-25 October 2013. CERN, Geneva .
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Ana MontanerPizá. Instituto de Física Corpuscular IFIC, Valencia, Spain. Isospin Mixing And In-beam Study Of 56Co Non-yrast States At MLL/Miniball. Motivation And First Glance On The Results Of The Experiment MINIBALL Workshop . 24-25 October 2013. CERN, Geneva.
Physics motivations • Starting point: Comparison of beta decay of 56Znwith its mirror process 56Fe(3He,t)56Co. Motivations: • Study of theγde-excitation of the IAS in 56Co. • Clarification of the Jπ assignment of two key levels in 56Co. At RCNP (Osaka, Japan) At GANIL (France)
56Co present knowledge • Present status of the 56Co nucleus from ENSDF Evaluated Nuclear Structure Data File Isospin mixed states 3076.0 keV, 1+ ? 2635.9 keV, 1+ ?
Studying the mirror process: Beta decay experiment at GANIL 4 EXOGAM clovers for gamma detection 4 EXOGAM clovers for gamma detection 4 EXOGAM clovers for gamma detection • The beta decay experiment was carried out at GANIL in 2010, focused on the production of 56Zn. (S. Orrigo, B. Rubio, Y. Fujita, W. Gelletly et. al.) • The analysis of this experiment is very advanced. In order to fully interpret this work a better understanding of the 56Co excited states will be crucial. 56Zn → 56Cu + β+ 56Zn
Motivation I: Study of theγde-excitation of the IAS in 56Co Isospin mixed states IAS • Very low Sp • Proton decay for the IAS is isospin forbidden gamma de-excitationispossible. Reference: S.E.A. Orrigo et al., INPC 2013 Proceedings, EPJ Web of Conferences(2013).
Motivation II: Clarification of the Jπ assignment of two key levels in 56Co (1) • The high energy-resolution 56Fe(3He,t)56Co reaction was carried out by Hiro Fujita et. al. at RCNP- Osaka. • According to their results, there exist serious doubts about the 1+ character of the states at 2.633MeV and 3.073MeV. Reference: "Isospinmixingfortheisobaricanalogstatestudied in a high-resolution56Fe(3He,t)56Co reaction". H. Fujita, Y. Fujitaet al., submittedto PRC.
Motivation II: Clarification of the Jπ assignment of two levels in 56Co (2) Well known 1+ distribution 2.633 MeV 3.076 MeV 2+ distribution Reference: "Isospinmixingfortheisobaricanalogstatestudied in a high-resolution56Fe(3He,t)56Co reaction". H. Fujita, Y. Fujitaet al., submittedto PRC.
MINIBALL experiment at the MLL (Munich) • Experiment carried out in the Maier-Leibnitz-Laboratorium(MLL) at the TechnischeUniversitätMünchen(TUM), in June 2013. • Reaction: 56Fe(p,n)56Co • 56Fe Target thicknesses: 1 and 2 mg/cm2 • Proton beam: 10 MeV and 12 MeV • Beam intensity: 1-3 nA • Duration: 6 day • Angle calibration reaction: 32S(d,p)33S in inverse kinematics.
Setup of the experiment MINIBALL clusters Beam direction MINIBALL cluster
Preliminary results of MINIBALL experiment at MLL Study of theγde-excitation of the IAS in 56Co. Isospin mixed states T=2 0+ IAS T=1 0+ 962 869 796 891 Either not there or much weaker, and we will get upper limits in due time 1806 1878 Gated in the 1185 keV line 1185 PRELIMINARY 962 keV 891 keV ?
Preliminary results of MINIBALL experiment at MLL (2) Clarification of the Jπ of the levels 3076 keV and 2636 keVin 56Co using angular correlations. Isospin mixed states T=2 0+ IAS T=1 0+ 962 869 796 891 PRELIMINARY 1185 keV peak 2635.9 keV 1806 1878 1185 Gated in the 480 keV line 480 Miniball: 4 clusters 3 crystal/cluster 6 segments/crystal 1185 keVpeak from the de-excitation of the 2635 keV level: # Counts: 1.12·105 # Counts per measurable angle: 1.12·105/(4x3x6) ≈ 1555
Conclusions • Stability and well behaviour of MINIBALL detectors. • Crosstalkproblem. • WehavetorestricttocoincidencesbetweendifferentClusters. • From the motivation point of view: • Angular correlations: we will be able to clarify the spin-assignment of the 2636 keV and 3076 keV states. • Gamma de-excitation of the two 0+isospin mixed states Weshould be ableto set meaningfulupperlimitstothose "new" two gamma linesfromthe de-excitation of the 0+ T=1 state. Analysis in progress. Verypreliminaryresultspresented.
A. Montaner-Pizá, B. Rubio, J. Agramunt, A. Algora, V. Guadilla, S. Orrigo. IFIC-Valencia, Spain. • D. Mücher, S. Reichert, S. Hellgartner, C. Berner. TUM, Munich, Germany. • B. Gelletly. Surrey University, U.K. • Y. Fujita. RCNP, Osaka, Japan. • E. Ganioglu, Istanbul University, Turkey. Thank you!