Dynamical versus statistical production of Intermediate Mass Fragments at Fermi Energies

Abstract

The Intermediate Mass Fragments emission probability from Projectile-Like Fragment break-up in semi-peripheral reactions has been measured in collisions of 124 Xe projectiles with two different targets of 64 Ni and 64 Zn at the laboratory energy of 35 A MeV. The two colliding systems differ only for the target atomic number Z and, consequently, for the Isospin N/Z ratio. An enhancement of Intermediate Mass Fragments production for the neutron rich 64 Ni target, with respect to the 64 Zn, is found. In the case of one Intermediate Mass Fragment emission, the contributions of the dynamical and statistical emissions have been evaluated, showing that the increase of the effect above is due to an enhancement of the dynamical emission probability, especially for heavy IMFs (Z 7). This proves an influence of the target Isospin on inducing the dynamical fragment production from Projectile-Like Fragment break-up. In addition, a comparison of the Xe+Ni,Zn results with the previously studied 112,124 Sn+ 58,64 N i systems is discussed in order to investigate the influence of the projectile Isospin alone and to disentangle between Isospin effects against systemsize effects on the emission probability. These comparisons suggest that the prompt-dynamical emission is mainly ruled by the N/Z content of, both, projectile and target; for the cases here investigated, the influence of the system size on the dynamical emission probability can be excluded.

Trends in particle and nuclei identification techniques in nuclear physics experiments

“…However, this method is also extensively used at higher energy, as we can see in Fig. 10b that shows an energy vs. rise-time plot obtained in the reaction 124 Xe + 64 Zn at 35 MeV/nucleon [46]. The energy threshold for the charge identification depends on Z; for example, it corresponds to 5.6 MeV/nucleon for Z = 6 and it increases to 9 MeV/nucleon for Z = 16.…”

“…The CHIRONE experiment operates in the field of nuclear reactions, covering a wide energy range, from few MeV/nucleon to the Fermi energy (around 40 MeV/nucleon), and using stable and unstable ion beams. In this framework, many physics cases have been studied, such as: isospin effects on formation and decay mechanisms of compound nuclei, dynamical and thermodynamical effects on nuclear reactions, structure of weakly bound light nuclei, collective behaviour of nuclei, symmetry energy term of equation of state (EoS) and clustering of light nuclei with also nuclear astrophysics implications [44][45][46][47][48].…”

“…However, the possibility to employ the pulse shape analysis in Si detectors expanded the energy regime towards lower energy (E ≤ 10 MeV/nucleon) [169]. In CHIMERA, the PSA in Si is based on the analysis of the rise time of Si signals, and it allows the identification in charge of slow-moving particles, stopped in Si detectors (with a thickness of 300 µm), having 3 ≤ Z ≤ 18 [46,170]. With the CHIMERA multidetector this technique is applied in Si direct configuration (i.e.…”

Studies of the equation-of-state of nuclear matter by heavy-ion collisions at intermediate energy in the multi-messenger era

“…In this case light IMFs that are formed from the neck fragmentation are expected to be more neutron rich depending on the stiffness of the symmetry energy at low density [2] as effectively has been experimentally probed [144,145]. Indeed, a rich physics connected to the isospin properties of the emitted fragments is related to the deformation and fission of the projectile-like fragment in the dynamical stage of the reaction [146,147] that seems promising to bring new knowledge into the EoS of asymmetric matter around or below ρ 0 .…”

NArCoS: The new hodoscope for neutrons and charged particles

“…In particular, thanks to the new facilities for radioactive ion beams (RIBs) that will be available in the future, it will be possible to reach large isospin asymmetry (beam) never obtained until now. Particle-particle correlations are a relevant technique to pin down this kind of information [1][2][3][4][5][6]. By using light-charged particle (LCP) correlations, many works have been conducted from theoretical and experimental perspectives in nuclear dynamics and nuclear structure studies with correlators of first [7,8] and second generations, such as FARCOS [9][10][11][12][13][14].…”