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Abstract.We extend the angular momentum correlation description of peripheral heavy-ion collisions to study the time evolution picture of their interaction process in terms of the time power spectrum. This is done for both strongly asymmetric mass and (quasi)symmetric mass colliding nuclei. It is found that the pole spin correlation function implies a physically meaningful description of the collision, while the Gaussian, Lorentzian and exponential correlation functions yield an unphysical picture involving simultaneous rotation of the dinucleus in two opposite directions from the near-side and in two opposite directions from the far-side. The difference between the time evolution laws yields the difference between the angular distributions. As an illustration we analyse angular distributions calculated with different spin correlation functions. The pole spin correlation gives a good fit for the experimental angular distributions in the 2sSi + 64Ni (El~b = 123 MeV) dissipative collision, while the corresponding predictions using Gaussian, Lorentzian and exponential spin correlations are in disagreement with the data.

Section: Introductionmentioning

confidence: 86%

Time evolution of collision process and applicability of angular momentum correlation description for heavy-ion reactions

Kun¹,

Papa

Robson³

1993

“…Since the discovery of fluctuations in the excitation functions of dissipative heavy-ion collisions (DHIC) [1 ], further experiments [2][3][4][5][6] have shown that this phenomenon is universal for relatively light systems with masses A 1 + A 2 < 100. The existence of fluctuations reflects channel-channel correlations in such processes.…”

Section: Introductionmentioning

confidence: 99%

The effect of angular-momentum dissipation on fluctuations of excitation functions in heavy-ion collisions

Kun

Nörenberg

1992

We discuss here the effect of dissipation of relative angular momentum on fluctuations of excitation functions in dissipative heavy-ion collisions. Dissipation and fluctuation of relative angular momentum modify and smooth the time-angle localization of the rotating dinuclear system. The secondary maxima in the energy correlation function of the cross-section shift to smaller values of the energy difference, the shift depending on the relaxation time and the diffusion coefficient for angular-momentum dissipation. The results are illustrated for the collision 28Si(E1ab = 130 MeV) + 48Ti.

“…The presence of strong fluctuations in the excitation functions of Dissipative Heavy Ion Binary Collisions (DHIBC) [1][2][3][4][5] has been the object of increasing interest in the last years. Unexpected new features of the experimental data have been interpreted in the framework of theories which assume as underlying basic idea the presence of angular momentum coherence between the levels of the intermediate dinuclear system [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Study of the excitation function fluctuations of the dissipative28Si+48Ti binary collision in the incident energy interval from 206.9 MeV to 213.8 MeV

Rizzo

Cardella

Rosa

et al. 1994

Abstract.It is shown that the Partially Overlapping Molecular Level Model (POMLM) accounts for the experimental results of the dissipative 28Si+ 4STi collision around 210 MeV incident energy. The general trend of the properties of the fluctuations as well as the average angular distributions are reproduced by the same set of main parameters. A general consistency is also found between the present data and the data obtained in previous work on the same colliding system performed at lower incident energy (around 123 MeV).