Evidence of non-statistical structures in the elastic and inelastic scattering of58Ni+58Ni and58Ni+62Ni and intermediate dinuclear states

Abstract

Excitation functions and angular distributions of 58 Ni+ 58 Ni and 58 Ni+ 62 Ni scattering at energies just above the Coulomb barrier have been measured around θ cm = 90 • in energy steps ∆E cm = 0.25 MeV from E cm 110 MeV to E cm 120 MeV for 58 Ni+ 58 Ni and from E cm 110 MeV to E cm 118 MeV for 58 Ni+ 62 Ni. Evidence for structure of non-statistical character has been found in the angle-summed excitation functions; this evidence is corroborated by the analysis of the angular distributions. This is the first time that non-statistical structure in elastic and inelastic scattering is reported with high confidence level for this mass and excitation energy ranges. Attempts are presented to understand the nature of this structure, including the presence of intermediate dinuclear states and virtual states in a potential well.

Nonstatistical fluctuations for deep inelastic processes inAl27+Al27Berceanu1, Dūma2, Moisă3 et al. 2006Phys. Rev. C1020View full textAdd to dashboardCite

“…The predictions of the OCM were extended to almost symmetric heavier systems such as 58 Ni+ 58 Ni and 58 Ni+ 62 Ni. These predictions were in general confirmed by the experiments at low incident energies [15,16]. In the case of DHIC one remarks that, except light systems, the nonstatistical fluctuations were observed in quite asymmetric non-α medium systems.…”

“…where R int = r • (A It was also necessary to consider larger momenta of inertia to explain the period of the secondary oscillations observed in the EAF for other systems ( 12 C+ 24 Mg, 24 Mg+ 24 Mg, and 28 Si+ 28 Si) in this mass region [19,20], whereas the period of the secondary structures in the EAF for heavier systems ( 19 F+ 89 Y [32], 58 Ni+ 58 Ni, 58 Ni+ 62 Ni [16], 58 Ni+ 46 Ti [42]) could be explained using the momentum of inertia calculated at R int . This shows the possibility of the existence of superand hyperdeformation in this mass region, as it was predicted 30 years ago [43].…”

Statistical reactions with memory and thermalized-nonequilibrated nuclear states

“…In particular, memory effects are suggested [24] to be a sufficient condition to explain nonselfaveraging of the excitation function oscillations in dissipative heavy-ion collisions [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46]. It has also been found that spin and parity S-matrix correlation allows one to account for the oscillating non-Lorentzian behaviour of the cross section energy autocorrelation functions in 58 Ni + 62 Ni elastic and inelastic scattering [47].…”

Nuclear Structure With the Dinuclear Model

“…Nuclear molecular states were first observed in the 12 C -12 C collision by Bromley et al [6] and then seen up to the system Ni + Ni by Cindro et al [7]. The question arises whether heavier nuclear systems have excited states with the properties of molecular (or cluster) states.…”

“…7 show calculated reduced electric multipole moments for 226 Ra as a function of nuclear spin in comparison with experimental data (from[21]). The obtained values (also of other actinides) are in qualitative agreement with the known experimental data for Q exp λ with some exceptions, e.g.…”