According to the large variety of subjects presented in the SPIRAL2
Letter of Intent, a ‘Physics Cases and Theory’ working group has been formed at
the very beginning of the
In the course of its first half-year of operation, the contacts
established with the theoreticians involved already at the time of the preparation
of the Letter of Intent, but also with a few others, have been strengthened. While
triggering these discussions, the group succeeded in creating a smooth synergy
between the various goals and requests expressed within the collaboration. A
summary of this first working stage has been presented at the PARIS meeting held
in Cracow in May 2007.
In a second stage, the vivid interest manifested by several teams to
join the collaboration raised the question about enlarging even more the
ambitious physics program of
List
of requirements related to the different physics cases to be addressed at PARIS
Physics Case |
Recoil mass |
v/c [%] |
Eg range [MeV] |
DEg/Eg [%] |
DEsum/Esum [%] |
DMg |
W coverage |
DT [ns] |
Ancillaries |
Comments |
Jacobi transition |
40-150 |
<10 |
0.1-30 |
4 |
<5 |
4 |
2p-4p |
<1 |
AGATA HI det. |
High eff. Beam rej. |
Shape Phase Diagram |
160-180 |
<10 |
0.1-30 |
6 |
<5 |
4 |
2p-4p |
<1 |
HI det. |
High eff. Differential method Beam rej. |
Hot GDR in n-rich nuclei |
120-140 |
<11 |
0.1-30 |
6 |
<8 |
4 |
2p-4p |
<1 |
HI det. |
Beam re. |
Isospin mixing |
60-100 |
<7 |
5-30 |
6 |
- |
- |
4p |
<1 |
HI det. |
High eff. Beam rej. |
Reaction dynamics |
160-220 |
<7 |
0.1-25 |
6-8 |
<8 |
4 |
2p |
<1 |
n-det. FF det. |
Complex coupling |
Collectivity vs. multi- fragmentation |
120-200 |
<8 |
5-30 |
5 |
- |
- |
2p |
<1 |
LCP det. HI det. |
Complex coupling |
Radiative capture |
20-30 |
<3 |
1-30 |
<4 |
5 |
- |
4p |
<1 |
HI det. |
High eff. |
Multiple Coulex |
40-60 |
<7 |
2-6 |
5 |
- |
- |
2p |
<5 |
AGATA CD det. |
Complex coupling |
Astrophysics |
16-90 |
0.1 |
0.1-6 |
6 |
5 |
- |
4p |
<1 |
Outer |
High eff. Back-ground |
Shell structure at intermediate energies (SISSI/LISE) |
16-40 |
20-40 |
0.5-4 |
3 |
- |
- |
3p |
<<1 |
SPEG or VAMOS |
High eff. Low Ibeam g-g coinc |
Shell structure at low energies (separator part
of S3) |
30-150 |
10-15 |
0.3-3 |
3 |
- |
- |
3p |
<<1 |
Spectrometer part of S3 |
High eff. Low Ibeam g-g coinc |
Relativistic Coulex |
40-60 |
50-60 |
1-4 |
4 |
- |
1 |
Forward 3p |
<<1 |
AGATA HI analyzer |
Ang. Distr. Lorentz boost |
In line with
the above, the group is nowadays investigating how accurately a given physics
point can be probed with the resolution to be foreseen in experiment. This study
is progressively deepened thanks to the fast progress of the ‘Simulations’
working group. It recently led to concrete propositions for the key experiments
to be run at the different stages of the development of the device.
As priority
flagship experiments, two reactions among the early physics cases of the Letter of Intent (Jacobi transition
and radiative capture) have already been chosen, and the most relevant system
concerned with the new
(1) Seven physics cases have been presented in the SPIRAL2 Letter of Intent.
They are:
- Jacobi shape transitions (A.Maj, J.Dudek)
- Shape phase diagrams with the GDR
differential method (A.Maj, I.Mazumdar)
- Hot GDR studies in neutron-rich nuclei
(D.R.Chakrabarty, M.Kmiecik)
- Isospin mixing at finite temperature (M.Kicinska-Habior)
- Onset of multifragmentation and GDR (J.P.Wieleczko)
- Reaction dynamics around the barrier by means
of γ–ray measurements (C.Schmitt, O.Dorvaux)
- Heavy-ion radiative capture (S.Courtin,
D.Jenkins)
(2) Five more topics are seriously envisaged to be added to the early
- Multiple (normal) Coulex (P.Napiorkowski,
F.Azaiez, A.Maj)
- Shell structure at intermediate beam energies
(Z.Dombradi, F.Azaiez)
- Nuclear astrophysics (S.Harisopulos)
- Relativistic Coulex (P.Bednarczyk)
- Shell structure with PARIS@S3 (F. Azaiez)