INIZIATIVA SPECIFICA LS31

Dinamica Nucleare in condizioni estreme
Coord.Naz.: M.Di Toro, LNS Catania

Richiesta 2007

Proposal Description

Nuclear Dynamics under extreme conditions

The project represents a well established collaboration
between nuclear theorists working at the Laboratori Nazionali del Sud (LNS) and in the INFN Sezione di Firenze (FI).
The aim is to develop new trends in nuclear dynamics of
large interdisciplinary interest, like the nuclear
collective response in stable and unstable regions, the
competition between regular and chaotic motion in correlated systems, the nuclear equation of state under extreme isospin and density conditions, the phase transitions in nuclear systems.
In particular in the last year some attention has been focussed on problems of astrophysical interest, like
isospin effects at high baryon densities and the possibility of hybrid hadron-quark neutron stars, and on chaos driven fusion enhancement in plasmas, of relevance for reaction cross sections in stars as well as for energy production via fusion.
From the fundamental side the project is largely devoted to the selection of "Observables" in the reaction dynamics, from low to relativistic energies, that we expect to be particularly sensitive to the effective nuclear interaction in the medium. The aim is to be able to set some physical constraint at the intermediate level of effective field approaches.
Within this frame a great effort is put in maintaining
always a close collaboration with experimental groups. Members of the collaboration are actively participating in NuPeCC working groups, in particular in the discussion of the new European Radioactive Beam Facilities and in general
of the Long Range Plan. An optimal exchange of ideas and
information has been established with experimentalists
working at the new projects of GANIL(Spiral2) and GSI(Compressed Matter).
The LNS group has been among the promoters of the
World Consensus Initiative to coordinate at planetary level
the physics of the nuclear reactions at the Fermi Energies.

In the following the main results obtained in the last
year are listed,including the corresponding team links
and collaborations. A detailed list of publications is
reported in connection to each team:

1)
1a: Stable and unstable collective nuclear response
- Collective modes of deformed nuclei and clusters:
a kinetic approach.
- Semiclassical Pairing for the low energy nuclear
response.
- Relativistic transport approach to collective nuclear
dynamics.
1b: Nuclear fragmentation and liquid-gas phase transition.
- Dynamical mechanisms based on the spinodal decomposition
- Mid-rapidity emissions and neck instabilities
- Fluctuations in transport approaches microsocopic
implementation of a Boltzmann-Langevin equation for
fermionic systems.


Linkage: LNS and FI groups. Collaborations with
Oxford (D.Brink), Santiago (F.A.Brieva), Kiev (V.Abrosimov),
Bucharest (V.Baran, A.Raduta), Smith College (US, M.Pfabe'),
GANIL (P.Chomaz), Munich (T.Gaitanos, H.H.Wolter) and Mersin (S.Yildirim).
Connections to exps. performed at MSU, Cycl.Inst.College
Station, GANIL and Laboratori Nazionali di Legnaro (LNL).

2) Transport approaches and critical phenomena
- Chaos driven fusion enhancement at astrophysical
energies.
- Fusion in Plasmas.
- Muon catalyzed fusion.
- Constrained molecular dynamics approach to fermionic
systems.

Linkage: LNS and FI. Collaborations with Buenos Aires
(C.Dorso), JAERI (T.Maruyama), Tohoku (N.Tagikawa) and
N.Dehli (J.De, S.Samaddar).

3) Equation of State of Nuclear Matter
- Transport properties of the symmetry term.
- Density dependence of the symmetry term.
- Nucleon effective masses in asymmetric matter and
the energy dependence of the Lane potential.
- Three body forces in the isovector channel
- Microscopic approaches and predictions for stellar
evolution and neutron star properties: spin
polarization and superfluididy.
- Hybrid (hadron-quark) neutron stars from density
dependent bag models.
- Kaon condensation in neutron stars.
- Effective Field Theories: the Lorentz structure of
the symmetry term.
- EOS-sensitive observables: Flows and Stopping.
- Kaon production as a probe of the high baryon density
phase.
- A new mixed quark-hadron phase of matter at high baryon
and isospin density: exotic expectations.

Linkage: FI and LNS. Collab.s with Liege (A.Lejeune),
Orsay (P.Schuck and N.Van Giai), Kurchatov (E.Saperstein
and M.Zverev), Lanzhou (W.Zuo), Munich(T.Gaitanos,H.Wolter),
Tubingen (Ch.Fuchs), Giessen (H.Lenske), IHEP Beijing (Liu Bo, X.J.Peng), CIAE Beijing (Z.Y.Ma and C.W.Shen), Ferrara (A.Drago) and Torino (A.Lavagno).
Connections to exps. performed at GSI, FOPI and ALADIN
collaborations.

In the last year the LS31 collaboration has published
several papers and reviews in international journals and
presented numerous contributions and invited talks at
international conferences and schools.