1. Rotational bands in the rare-earth proton emitters and neighboring nuclei Darek Seweryniak Argonne National Laboratory PROCON-2003 1.Rotational landscape in the rare- earth region. 2.Recoil-Decay Tagging. 3.Excited states in the proton emitters 147 Tm, 141 Ho and 131 Eu. 4.Particle-Rotor calculations. 5.GAMMASPHERE+  Ball+nWall. 6.Excited in 143 Ho and neighboring nuclei. 7.Summary and outlook.

2. Collaboration D.Seweryniak, C.N.Davids, M.P.Carpenter, S.Freeman, A.Heinz, G.Mukherjee, A.Sonzogni, J.J.Uusitalo, R.V.F.Janssens, T.L.Khoo, F.G.Kondev, T.Lauritsen, C.J.Lister, G.L.Poli, P.Reiter, I.Wiedenhoever Argonne National Laboratory P.J. Woods, T. Davinson University of Edinburgh J.J. Ressler, J. Shergur, W.B. Walters University of Maryland J.A. Cizewski, K.Y. Ding, N. Fotiades Rutgers University

3. Proton drip line 131 Eu 141 Ho 147 Tm

4. Nilsson diagram 147 Tm 135 Tb 141 Ho 131 Eu 145 Ho?

5. Strong coupling Coupling to the deformation axis: K is a good quantum number j precesses around the symmetry axis Coriolis introduces K-mixing signature splitting  4 and  enhances K-mixing R j K K K+1 K+2 K+3 K+1 K+2 K+3 K+4  K=1 Coriolis mixing K+4 E2 M1 E2 K-bandK+1 band

6. Rotational coupling Coupling to the rotational axis: j precesses around the rotational axis energies similar as in the gs band in the daughter small deformation, high-j, low-K R j  Strong Coriolis interaction j j+2 j+4 j+6 E2

7. Recoil-Decay Tagging Prompt  rays Recoils Implants  and p decays GAMMASPHERE Spatial and time correlations in the DSSD

8. Excited states in 147 Tm p (h 11/2 )p (d 3/2 ) 620 |  |=0.13 GS data - 4 hours Aye-ball data

9. 141 Ho spectra

10. 141 Ho level scheme 7/2 - [523]½ + [411] D. Seweryniak et al., PRL C86(2001)1458 Unexpectedly large signature splitting!  =0.25(4) Harris formula pp

11. Particle-Rotor Model Input  Tri-axial Rotor  Woods-Saxon potential with the universal set of parameters  Coriolis attenuation factor 0.85  Proton pairing strength 0.136 MeV  Moments of inertia adjusted to the 2+ energy in the daughter nucleus Coriolis matrix elements are attenuated by the pairing factor: u 1 u 2 +v 1 v 2

12.  =0.25-0.31  =0 o -(-20 o )  =100-90%  =100-90%   =0-(-0.06) 7/2 - 9/2 - 11/2 - 13/2 - 15/2 -  =180-200 exp  =0.29,  4 =0,  =0 o PR model sensitivity

13. 141 Ho Particle-Rotor calculations Best fit:  2 =0.25 E(2 + )=190 keV  4 =-0.06  =-10 o Another fit:  2 =0.29 E(2 + )=140 keV  4 =-0.06  =-20 o

14. Total Routhian Surface Calculations  =0.25 MeV  =0.05 MeV  =0.15 MeV  =0.35 MeV 141 Ho is  soft and develops triaxiality at higher angular momentum

15. 131 Eu spectra M1 E2 h 11/2 band

16. 131 Eu level scheme 5/2 + [413] or 3/2 + [411] ground state? 3/2 + [411] band in 159 Tb 94 after A 5/3 scaling gives: 189 72 105 7/2+ 5/2+ 9/2+ 5/2 + [413] band in 159 Eu 96 after A 5/3 scaling gives: 237 104 134 7/2+ 5/2+ 9/2+ We observe 72 keV and 105 keV. Low energy transitions present in the spectrum suggest the 3/2+[411] assignment

17. Population of proton rich nuclei along the proton drip-line Z=72 154 Hf 153 Lu 152 Lu 151 Lu 150 Yb 149 Tm 148 Tm 147 Tm 150 Lu 146 Tm 146 Er 145 Tm 145 Ho 144 Ho 143 Ho 142 Ho 141 Ho 140 Ho 144 Dy 143 Dy 142 Dy 141 Dy 140 Dy 139 Dy 143 Tb 142 Tb 141 Tb 140 Tb 139 Tb 138 Tb 142 Gd 141 Gd 140 Gd 139 Gd 138 Gd 137 Gd 141 Eu 140 Eu 139 Eu 138 Eu 137 Eu 136 Eu CN 136 Gd CN pp ppp pp N=82 135 Eu 131 Eu … 50  b 300 nb500 mb 1 out of 10 million  rays! 5b5b 100 mb p

18. GAMMASPHERE  Ball+nWall http://wunmr.wustl.edu/~dgs/mball/ p,  n 54 Fe  P  n   Ball - 96 CsI nWall 30 NE203 92 Mo

19. Gamma spectra 143 Tb(3p) 143 Dy(2p1n) 142 Dy(2p2n) 63 Zn(2p1n) on C

20. 143 Ho level scheme 143 Ho(p1n2) 318 508 663 143 Ho 11/2 - 15/2 - 19/2 - 23/2 -

21.  E(2 +,0) and  E(15/2 -,11/2 - ) systematics 149 Tm 148 Tm 147 Tm 146 Tm 146 Er 145 Tm 145 Ho 144 Ho 143 Ho 142 Ho 141 Ho 140 Ho 144 Dy 143 Dy 142 Dy 141 Dy 140 Dy 139 Dy 143 Tb 142 Tb 141 Tb 140 Tb 139 Tb 138 Tb 142 Gd 141 Gd 140 Gd 139 Gd 138 Gd 137 Gd 141 Eu 140 Eu 139 Eu 138 Eu 137 Eu 136 Eu 464 318 203 487 145 Er 144 Er 323526273 307521 316493 515329221 169 145 Tm similar to 143 Ho!

22. Summary 1.Studies of excited states proved to be a very useful source of complementary information on proton emitters. 2.Ground state band in 147 Tm confirmed and extended. 3.Lower  2 deformation in 141 Ho,  4 and  important. Single –particle configurations in agreement with adiabatic decay-rate calculations. 4.Rotational bands in 131 Eu observed. Fine structure confirmed. The 3/2+[411] assignment is favored. 5.The h 11/2 band in 143 Ho observed, more to come ….

23. Outlook 1. 1.Recent upgrades of the FMA implantation station and GAMMASPHERE promise next successful RDT campaign. 2. 2.GAMMASPHERE+FMA will allow to study excited states in other, recently discovered deformed proton emitters such as 117 La or 145 Tm. 3. 3.GAMMASPHERE+  Ball+nWall will allow to fill up considerably the gap between the stability line and the proton drip line. 4. 4.Other methods such as RDT using  - delayed proton emitters or isomer studies could also contribute.