1. Heavy-Ion Binary Reactions
as a Tool for Detailed Gamma Spectroscopy in Exotic Regions
Silvia Leoni
University of Milano & INFN

2. LOI Collaboration AGATA- PRISMA collaborations
Milano University and INFN
A. Bracco, G. Benzoni, N. Blasi, F. Camera, F. Crespi, S. Leoni, B. Million, O. Wieland et al.
P.F. Bortignon, G.Colò, E. Vigezzi et al.
Legnaro INFN Laboratory
L.Corradi, G. DeAngelis, E. Fioretto, D. Napoli, A. Stefanini, J.J. Valiente-Dobon, et al.
Padova University and INFN
D. Bazzacco, E. Farnea, S. Lenzi, S.Lunardi, G. Montagnoli, D.Montanari, F.Scarlassara, C.Ur, et al.
Torino University and INFN
G. Pollarolo
IFIC, CSIC-University of Valencia, Spain
A. Gadea, …
Krakow, Poland
A. Maj, P. Bednarczyk, B. Fornal, M. Kmiecik, M. Ciemala et al.,
Ruder Boskovic Institute, Zagreb
S. Szilner, T. Mijatovic et al.
AGATA- PRISMA collaborations

3. Multi-Nucleon Transfer Reactions as a TOOL to study n-rich nuclei
CLARA/AGATA–PRISMA LNL since …
Structure of moderately n-rich nuclei
using most n-rich beams by PIAVE-Tandem-ALPI (5-10 MeV/A)
48Ca
40Ar
36S
26Mg
64Ni
70Zn
82Se
96Zr
136Xe
48Ca
66Ni
64Ni
46Ca
Multi-nucleon transfer
A~50
48Ca + 6MeV/A

4. CLARA (ex-EUROBALL)/AGATA – PRISMA setup
Legnaro National Laboratory INFN (Italy)
PRISMA
ΔΩ = 80 msr
ΔZ/Z  1/60
ΔA/A  1/190
Energy acceptance ±20%
Bρ = 1.2 Tm
CLARA (now AGATA)
25 EUROBALL HpGe Clover
~3 % @ Eγ= 1.3 MeV
2 p solid angle
3 rings at 100°, 130°, 150°
High-Efficiency g - particle coincidence Measurements

5. First Excited States of Exotic Nuclei
A & Z identification
64Ni + 238U @ 6.3 MeV/A Cr
(-4p) Fe
(-2p)
S. Lunardi et al., PRC76(2007)034303
N. Marginean et al., PLB633(2006)696
Shape Evolution in Cr and Fe isotopes
-2p+2n
-4p
+2p
+1p
-1p
-2p
-3p
-4p
-5p
-6p
Beams ~ 109 pps

6. Complete g-Spectroscopy: Ip and B(El)
Plunger
lifetime
48Ca + 64Ni @ 6 MeV/A
Angular Distribution
and Polarization
49Ca E1 E2
7/2-
9/2+
3-p3/2 : coupling
octupole Phonon -
single particle
7 Wu
Tentative Ip
0.05 Wu
MNT Reactions: Strong SPIN Alignment perpendicular to reaction plane
D. Montanari et al., PLB697(2011)288 and J.J. Valiente-Dobon et al., PRL102(2009)242502

7. FIRST EXAMPLE of Multi-Nucleon transfer with RIB
24Ne MeV/A
EXOGAM + VAMOS
SPIRAL Beam 24Ne ~ pps
Study of Reaction Dynamics and
First excited states mostly in ONE nucleon transfer channels
G.Benzoni, F.Azaiez et al., EPJA45(2010)287
24Ne
25Ne
+1n
23F
-1p
2+  0+
Semiclassical model GRAZING gives reasonable agreement
also for reactions with radioactive beams
G. Pollarolo. A.Winther, Nucl.Phys.A594 (1995)203

8. Multi-Nucleon transfer with SPES beams
Physics Cases with pps
1 - g spectroscopy around 132Sn
2 - r-process nuclei beyond N=50
Multi-Nucleon transfer with SPES beams
@ 5-10 MeV/A
SIMILAR/BETTER quality as today experiments (with 109 pps)
 factor  3 higher detection efficiency (CLARA GALILEO/AGATA)
 factor 3 longer beam time (1 week 3 weeks)

9. CASE 1: g spectroscopy around 132Sn
STUDY OF
Single particle states
particle-phonon couplings
high spins
Ip, B(El)
Z=50
Complementary to
Fission and b-decay
Coulomb excitation
Transfer with light targets
(d,p), (d,t), …
N=82
10 mb
1 mb
SPES Beams
130Sn
131Sn
132Sn
133Sn
134Sn
5 105
129In
130In
131In
132In
133In -
128Cd
129Cd
130Cd
GRAZING calculations
Conservative estimates for more than 1 nucleon transfer

10. FOCUS on Particle-Phonon Coupled States
Favourable population by Heavy-Ion Reactions
excited core
(phonon)
Coupling with 1 particle
- effective single particle levels
- coupling strength
Coupling with 2 particles
- core + 2 particles model
- physics of pairing
Near
DOUBLY MAGIC
nuclei
M.B. Tsang et al. PRL102(2009)062501 Ni
±40%
(Theory)
(EXP)
Key Ingredients for understanding of
Quenching of Spectroscopic Factors
Anharmonicity of vibrational spectra
Damping of Giant Resonances, …
SOURCE OF DISCREPANCY with SHELL MODEL: CORE Excitations
 Need of CORRELATIONS only partially included in Shell Model

11. 132Sn – 133Sn Collective Properties of 132Sn:
208Pb
132Sn
Spectroscopic
factors
Collective Properties of 132Sn:
2+: E = 4041 keV, B(E2) = 7.2 Wu
3-: E = 4352 keV, B(E3) > 7 Wu
(d,p): 132Sn + CD2
K.L. Jones et al., Nature, 465(2010)454
Complemenary INFOs from MNT
Single particle states in 133Sn:
Low beam Intensity: ~ 105 pps
Extraction of SF (~ 30% error)

12. 131In – proton hole states 132Sn G.Colò and P.F.Bortignon pure
M.Gorska et al., PLB672(2009)313

13. 130Cd – 2 proton holes states
220 ns
Tentative Ip assignment
Tentative B(El) values
Missing levels
Strength of PAIRING interaction
SHELL quenching below 132Sn
GSI: Projectile fragmentation
136Xe (750 MeV/A) + Be
A. Jungclaus et al., PRL99(2007)132501

14. Systematic Study of PVC states around magic/doubly-magic nuclei
RESEARCH LINE:
Systematic Study of PVC states
around magic/doubly-magic nuclei
Coupling strength
Dependence on Fermi Surface Asymmetry (N/Z)
Up to now: Scarce Information Mostly in Heavy-Masses
209Bi: Bohr & Mottelson, Vol. II.
209Pb: P. Kleinheinz et al.,PRL48(1982)1457
207Pb: N. Pietralla et al., PLB681(2009)134
A ~ 200
A ~ Gd, 147Tb: P. Kleinheinz et al.,PRL48(1982)1457;
P. Kleinheinz, Physica Scripta 24(1981)236.
More recently: Evidence for PVC in A~50 Nuclei
49Ca: 4017 keV = 3-  p3/2
47Ca: 3999 keV = 3-  f-17/2
… Robustness of Collectivity of magic (light) core …

15. Experimental Signature
Multiplet of States: |l-j|  I  l+j
B(El) of phonon
3/2+
9/2+ 3/
7/2+
5/2+
E [MeV] 2 3 4
48Ca
B(E3)
6.8 ± 1.0 Wu
3-  p3/2
7 Wu
49Ca
Energy Split:
Coupling strength
Nuclear Force
48Ca
(Z=20,N=28)
(n,g) proposal
at ILL Grenoble
 3/2+ and 5/2+
Phys. Lett. B697(2011)288
Phys. Rev. C85(2012)044301

16. Theoretical Description
PHENOMENOLOGICAL
Particle-phonon
WEAK coupling calculations
(Bohr & Mottelson)
SLy5 - LNS
p 1d3/2 1f7/
2s1/2 1f7/
 1f7/2 1g9/
“SIMPLE” 
MACROSCOPIC
CORE
Vibration
Transition Densities
48Ca: 3- RPA calculations
3-  p3/2
[l  j1]I
49Ca
Multiplet of States /2+, 7/2+, 5/2+, 3/2+
Energy Shift
Lowest order
Perturbative Contributions
wl , B(El)
→ Exp. Values
s.p. Energies
e(j1), e(j2)
→ HF – SkX

17. Energy Density Functional
Theoretical Description
PHENOMENOLOGICAL
Particle-phonon
WEAK coupling calculations
(Bohr & Mottelson)
MICROSCOPIC
Calculations based on
SELF-CONSISTENT Scheme
Energy Density Functional
RPA
microscopic Vph
G. Colò, H. Sagawa, P.F. Bortignon, PRC 82, (2010).
Hartee-Fock with Veff
→ short-range correlations included
Particle-Vibration coupling on top
→ same Hamiltonian or EDF
NO approximation in the vertex
EXACT treatment of COUPLING
use of WHOLE phonon wave function
3-  p3/2
[l  j1]I
49Ca
Multiplet of States /2+, 7/2+, 5/2+, 3/2+
Energy Shift
Lowest order
Perturbative Contributions
wl , B(El)
→ Exp. Values
s.p. Energies
e(j1), e(j2)
→ HF – SkX
Need of More Experimental Input

18. WORK in PROGRESS: Study of PVC states around Ni isotopes
[l  j1]I
Multiplet of States
9/2+, 7/2+, 5/2+, 3/2+ 3-
B(E3)~15Wu
64,66Ni
(Z=28,N=36,38)
Superfluid Core in n
p coupling
pp3/2-
Approved Experiment
64Ni(7Li,)65Cu
Tandem-Bucarest
S. Leoni et al.
FAST TIMING
B(E3)~??? Wu
Existing Data
64Ni(,p)67Cu
N. Marginean et al.
FAST TIMING
t(9/2+)~150 ps
B(E3)~17(2)Wu

19. 66Ni (Z=28,N=38) : Superfluid Core
Single Particle Levels
Pairing Strength
Including
Pairing …
Coupling with proton
WORK in PROGRESS …
S. Bottoni, G. Colò, P.F. Bortignon, …

20. CASE 2: r-process nuclei beyond N=50
Shape changes
with N number
subshell
N=56
N=50
SPES Beams
90Rb
91Rb
92Rb
1 109
93Rb
94Rb
- 2p
- 1p
r-process
- 3p
94-96Kr
90-92Br
Only masses
- 4p
87-90Se
86-88As

21. Importance of Nuclear Deformation difficoult to extrapolate
for r-process
b-decay half-lives and neutron emission probabilities
are different in DEFORMED and SPHERICAL nuclei
tb SPH ~ 7 x tbDEF
PnSPH ~ 0.5 x PnDEF
Large uncertainty in
r-process location
difficoult to extrapolate
to more exotic regions
P. Moller et al., Phys. Rev. C67, (2003) and ref. therein.

22. APPROVED REX-ISOLDE Proposal
Gamma spectroscopy of n-rich 95,96,97Rb nuclei
by the incomplete fusion reaction of 94Kr on 7Li
Spokepersons: B. Fornal and S. Leoni
particle emission
94Kr + 7Li → 97Rb + a
ELAB = 3 MeV/nucleon
Sa  2.5 MeV
Production of the excited 97Rb
Subsequent evaporation of one or two neutrons  96Rb and 95Rb
population of
only one state
at ~14.5 MeV 
factor of
more expected
35-75 mb
for 97Rb (and 95Rb)
232 MeV
7Li a
6Li t
MINIBALL + Si Telescope
TEST of reaction mechanism
Spectroscopy of n-rich 95-97Rb
 expected population of NON-yrast states

23. to populate Highly-excited dipole states
CONCLUSIONS
Multi-Nucleon Transfer at 5-10 MeV/A
are powerfool tool to reach exotic nuclei
with most intense SPES beams Sn and 90-92Rb
g spectroscopy around 132Sn (PVC states)
r-process nuclei beyond N=50
WORK in Progress:
Systematic investigation of Particle-Phonon Couplings
in different MASS regions: Ca, Ni, …
Theoretical Investigation by Phenomenological/Microscopic Models
Complementary to SHELL MODEL
Comparison with Other Rection Mechanisms
to populate Highly-excited dipole states
 preparatory work is needed
excitation function with stable beams MeV/A

24. Thank you for the attention

25. Spectroscopic Factors
Nature and Occupancy of single-particle orbits
Interplay Single-Particle and Collectivity
 Crucial test of Shell Model and Interactions
Source of discrepancies
Core excitations
State fragmentation
M.B. Tsang et al. PRL102(2009)062501 Ni
±40%
(Theory)
(EXP)
A. Gade et al. PRC77(2008)044306
Dependence on Fermi Surface
Enhanced CORRELATIONS in
Strongly bound valence nucleons

26. HOT topic in Nuclear Physics
Evolution of Shell Structure with N/Z
Search for Shell closures, Magic Numbers
Nature Effective Nuclear Force: 2-body, 3-body, …
Doubly Magic Nuclei
Near to Magic Nuclei
(1 and 2 nucleons away)
Among EXPERIMENTAL TOOLS
Coulex
Collectivity B(E2), B(E3), …
Knock-out, transfer reactions, …
Spectroscopic Factors
Purity of nuclear states
Single particle (SF 1)
Correlations (SF <1)
HOT topic in Nuclear Physics