Long-range angular coherence as orbiting phenomenon in dissipative collisions

Self Cite

Abstract. The properties of the strong fluctuations observed in the excitation functions of Dissipative Binary Heavy Ion Collisions (DBHIC) have been studied for the system 2Ssi+ 28 Si in the energy range 150MeV < El~b _< 156MeV with 150keV step laboratory incident energy, by angular distributions and excitation functions measurements. Experimental results are compared to the the recently developed Partially Overlapping Molecular Level Model (POMLM). The parameters of the model have been determined with reasonable accuracy by describing all the quantities characterizing the fluctuations in the excitation functions i.e.: Average Angular Distributions, Energy Autocorrelation Functions, Variances, Angular Correlation Coefficients. The results of the analysis strongly support the idea of a process proceeding through the formation of an highly excited "nuclear molecule". Experimental data collected at the most forward angles show the effects of strong excitation of a few final channels.

Section: Review Of the Theoretical Model And Analysis Of Datamentioning

confidence: 98%

Section: Review Of the Theoretical Model And Analysis Of Datamentioning

confidence: 99%

Highly excited “nuclear molecules”: A way to explain the fluctuations in DBHIC excitation functions. Study of the28Si +28Si colliding system at 5.3 MeV ·A

Papa

Cardella

Pietro

et al. 1995

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“…The sum over n includes contributions resulting from multiple rotations of the dinucleus. Under the condition of a constant value of the average relative angular momentum L, the rotation angle ~(t) is uniquely defined by (10), with co = L/ ~I, (12) where ~el is the relative moment of inertia of the dinucleus. Therefore, if dissipation of relative angular momentum becomes important, relations (10) and (12) are no longer valid.…”

Section: P(t O)-p(t O ~(T))mentioning

confidence: 99%

“…This phenomenon can be explained in terms of a Regge-pole representation for the partial reaction amplitudes [9][10][11][12]. This allows angular-momentum correlations, which are responsible for angular focussing in * Partly supported by the Alexander von Humboldt Foundation DHIC, to be taken into account.…”

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.

“…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

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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).