Core-excited states in 101Sn

Darek Seweryniak, ANLGS/FMA collaboration

Self-conjugate

Z

GT -decay

super allowed -decay

spe

p decay

n-n interactions

100Sn

rp processend point

N

Doubly-magic

100Sn physics

p

100Sn region experimental status

Z=50 101Sn102Sn 103Sn

102In101In99In 100In98In

101Cd

99Ag 100Ag

99Pd

104Sb

105Te

103Sb

99Cd 100Cd98Cd97Cd96Cd

95Ag94Ag96Ag 97Ag 98Ag

94Pd 95Pd 96Pd 97Pd 98Pd93Pd92Pd

106Te

108I

109Xe

112Cs

114Ba

113Cs

109I

105Sb

107Te 108Te

110Xe 111Xe 112Xe

104Sn

115Ba 116Ba

100Sn

Excited statesFusion-evaporation

Decay propertiesFusion-evaporation

Decay propertiesExistenceFragmentation

CN

CN

CN

CN

CN

103InCN

CN

99Sn

95Cd

N=50

-delayed protonswith sizeable branchObserved/expected

97In

93Ag

100Cd

101Ag

100Pd

101Sn p recoil-decay tagging experiment

101Sn

100Cd

p

Total spectrum

101Ag

Random

Ep=1-5 MeVtp<5s

rays

101Sn

g7/2

d5/2

172 keV

GAMMASPHERE+FMAFirst observation1st exp PRL 99, 022504 (2007)Search for core excited states2nd exp summer 2008

105Te decay indicates that the level sequence is different in 105Te and 101Sn (ORNL)

Core-excited states in 101Sn

7/2+

5/2+

5/2+

7/2+

Fahlander et al., Phys. Rev. C63, 021307(R) (2001)

• 100Sn(2+) coupled to d5/2 and g7/2 states ~2.5 MeV• h11/2 single-neutron orbital ~2.5 MeV• Feeding pattern can reveal the d5/2, g7/2 orbital order• Other nuclei of interest: 105Te, 100In

Can we collect more statistics with GRETINA+FMA?

4 times larger solid angle (possibility to use 3n channel) Higher Ge rates (higher beam intensity) Much better Doppler correction (3 MeV) Polarization (h11/2) No dead time Neutron Wall (Chris Chiara)

VERY CHALLENGING EXPERIMENT!Original experiment: ~5 days, ~10 kHz/Ge, ~10s nb

Interplay between rotation and proton decay in highly-deformed proton emitters

Darek Seweryniak, ANLGS/FMA collaboration

Proton decay vs rotation

Proton decay probes single-particle wave function components

In deformed nuclei, protons are emitted from rotational band heads

Properties of rotational bands can shed light on the proton emitting states

Only very recently the quasi-particle non-adiabatic proton-decay model by Maglione et al. included Coriolis interaction and pairing consistently

The new model has to be confronted with more data

Proton emitter landscape

~20 mass units away from the line of stability

Often less exotic neighbors not known

Rotational bands in highly-deformed proton emitters

117La

131Eu

141Ho

145Tm

Several proton emitters were studied with GS and FMA

141Ho – strongly coupled bands built on gs and isomer

145Tm – decoupled h11/2 band

117La,131Eu –multiple bands, not enough statistics

Rotational bands in the deformed proton emitter 141Ho

D. Seweryniak et al., PRL C86(2001)1458

7/2-[523] ½+[411]

Unexpectedly large

signature splitting

indicates triaxial shape!

=0.25(4) from Harrisformula

131Eu level scheme

5/2+[413] or 3/2+[411] ground state?

3/2+[411] band in 159Tb94 after A5/3 scaling gives:

18972

1057/2+

5/2+

9/2+

5/2+[413] band in 159Eu96 after A5/3 scaling gives:

237104

1347/2+

5/2+

9/2+

We observed 72 keV and 105 keV.Low energy transitions present in the spectrum

suggest the 3/2+[411] assignment

117La proton emitter

Quasi-particle non-adiabatic model predicts that protons are emitted from a 7/2- member of the h11/2 band

Spectrum indicates 3/2+[422] band supported by adiabatic approach

Z.Liu et al., Physics Letters B 702 (2011) 24–27

Can we collect more statistics with GRETINA and FMA?

4 times larger FMA solid angle Higher Ge rates (more beam) Better Doppler correction Polarization No dead time

CHALLENGING EXPERIMENT!Original experiment: ~5 days, ~10 kHz/Ge, ~100s nb

Thank you for you attention!