In this work, we illustrate the basic development of the constrained molecular dynamics applied to the N-body problem in nuclear physics. The heavy computational tasks related to quantum effects, to the Fermionic nature of the system have been resolved out by defining a set of transformations based on the concept of impulsive forces. In particular, in the implemented version II of the constrained molecular dynamics model the problem related to the non-conservation of the total angular momentum has been solved. This problem affects other semi-classical microscopic approaches due to the ''hard core'' repulsive interaction and, more generally, to the usage of random forces. The effect of the restored conservation law on the fusion cross-section for the 40 Ca + 40 Ca system is also briefly discussed.

The experimental excitation function for the 7α de-excitation of 28 Si nuclei excited to high excitation energies in the collisions of 35 MeV/nucleon 28 Si with 12 C reveals resonance structures. The possibility that these structures may indicate the population of toroidal high-spin isomers such as those predicted by a number of recent theoretical calculations is discussed and the need for further investigations is emphasized.

We address the role of Coulomb interaction in the determination of densities and temperatures of hot sources produced in heavy ion collisions. Such quantities can be obtained from the quadrupole momentum and multiplicity fluctuations of the emitted light particles. In this paper we modify the method by taking explicitly into account Coulomb corrections. The classical and quantum limits for fermions are discussed. In the classical case we find that the temperatures determined from 3 H and 3 He, after the Coulomb correction, are very similar to those obtained from neutrons within the constrained molecular dynamics approach. In the quantum case, the proton temperature becomes very similar to neutron's, while densities are not sensitive to the Coulomb corrections.

40 Ca+ 40,48 Ca, 46 Ti reactions at 25 MeV/A have been studied using the 4π CHIMERA detector. An isospin effect on the competition between incomplete fusion and dissipative binary reaction mechanisms has been observed. The probability of producing a compound system is observed to be lower in the case of N≈Z colliding systems as compared to the case of reactions induced on the more neutron rich 48 Ca target. Predictions based on CoMD-II calculations show that the competition between fusion-like and dissipative reactions, for the selected centrality, can strongly constraint the parameterization of symmetry energy and its density dependence in the nuclear equation of state.Pacs: 21.65. Ef, 21.65.Mn, 25.70.Jj, 25.70.Lm Collisions between heavy ions with different neutronproton asymmetries offer a unique opportunity to study the equation of state (EOS) of asymmetric nuclear matter [1][2][3][4]. Accessing the density dependence of the symmetry energy has recently attracted the interest of the community due to its implications in both nuclear physics and astrophysics of neutron stars [2,5,6]. The isotopic composition of fragments produced in multifragmentation phenomena is being extensively studied at intermediate beam energies (E/A=20-100 MeV) bearing important information on the symmetry energy [7]. One aspect not yet fully investigated is represented by the effect of the isospin asymmetry on the fate of hot nuclear systems. The combined effects of the symmetry energy and of the repulsive Coulomb interaction can significantly affect the reaction mechanism and the rate of production of hot compound nuclei in heavy-ion reactions at low and intermediate energies [8][9]. The isospin N/Z-asymmetry can also play an important role in opening different decay channels for a hot nuclear system once this has been produced. In this respect, the limiting temperature of a nucleus is expected to depend on both its mass and its isotopic composition [10][11][12]. Experimentally, the observation of small isotopic effects on the temperatures of projectile spectators in relativistic heavy-ion collisions have been interpreted as a signal of no isospin dependence of nuclear limiting temperatures [13]. At lower beam energies, a mass and N/Z-asymmetry dependence in limiting temperatures have been explored by studying the population of the Giant Dipole Resonance (GDR) at high excitation energies [14]. A small difference in the limiting GDR excitation energy has been observed when comparing a symmetric N~Z system to a neutron rich system [15]. All these findings stimulate attempts to link N/Z effects on measured observables to the nuclear symmetry energy and its density dependence in the equation of state.In this work we explore isospin effects in heavy residue (HR) remnants produced in incomplete fusion reactions between projectile and targets with different N/Z asymmetries. The results on the competition between incomplete fusion and binary dissipative mechanisms are compared to simulations performed with a microscopic mode...

A method to determine the density and temperature of a system is proposed based on quantum fluctuations typical of Bosons in the limit where the reached temperature T is close to the critical temperature Tc for a Bose condensate at a given density ρ. Quadrupole and particle multiplicity fluctuations relations are derived in terms of T Tc . This method is valid for weakly interacting infinite and finite Boson systems. As an example, we apply it to heavy ion collisions using the Constrained Molecular Dynamics (CoMD) approach which includes the Fermi statistics. The model shows some clusterization into deuteron and α clusters which could suggest a Bose condensate. However, our approach demonstrates that in the model there is no Bose condensate but it gives useful informations to be tested experimentally. We stress the differences with methods based on classical approximations. The derived 'quantum' temperatures are systematically higher than the corresponding 'classical' ones. The role of the Coulomb charge of fragments is discussed.

A recently proposed method, based on quadrupole and multiplicity fluctuations in heavy ion collisions, is modified in order to take into account distortions due to the Coulomb field. This is particularly interesting for bosons such as d and α particles, produced in heavy ion collisions. We derive the temperatures and densities seen by the bosons and compare them to results of similar calculations for fermions. The resulting energy densities agree rather well with each other and with the one derived from neutron observables. This suggests that a common phenomenon, such as the sudden opening of many reaction channels and/or a liquid gas phase transition, is responsible for the agreement.

The plasma astrophysical S factor for the 3He(d,p)4He fusion reaction was measured for the first time at temperatures of few keV, using the interaction of intense ultrafast laser pulses with molecular deuterium clusters mixed with 3He atoms. Different proportions of D2 and 3He or CD4 and 3He were mixed in the gas target in order to allow the measurement of the cross section for the 3He(d,p)4He reaction. The yield of 14.7 MeV protons from the 3He(d,p)4He reaction was measured in order to extract the astrophysical S factor at low energies. Our result is in agreement with other S factor parametrizations found in the literature.

A nucleus is a quantum many body system made of strongly interacting Fermions, protons and neutrons (nucleons). This produces a rich Nuclear Equation of State whose knowledge is crucial to our understanding of the composition and evolution of celestial objects. The nuclear equation of state displays many different features; first neutrons and protons might be treated as identical particles or nucleons, but when the differences between protons and neutrons are spelled out, we can have completely different scenarios, just by changing slightly their interactions. At zero temperature and for neutron rich matter, a quantum liquid gas phase transition at low densities or a quark-gluon plasma at high densities might occur. Furthermore, the large binding energy of the α particle, a Boson, might also open the possibility of studying a system made of a mixture of Bosons and Fermions, which adds to the open problems of the nuclear equation of state.