COMPARISON OF THE FUSION-FISSION AND QUASIFISSION MECHANISMS IN HEAVY-ION COLLISIONS

2009 ◽  
Vol 18 (04) ◽  
pp. 841-849 ◽  
Author(s):  
AVAZBEK NASIROV ◽  
GIOVANNI FAZIO ◽  
GIORGIO GIARDINA ◽  
GIUSEPPE MANDAGLIO ◽  
MARINA MANGANARO ◽  
...  
Keyword(s):  
Cross Sections ◽  
Theoretical Method ◽  
Heavy Ion ◽  
Evaporation Residue ◽  
System Model ◽  
Complete Fusion ◽  
Dinuclear System ◽  
Ion Collisions ◽  
Partial Fusion ◽  
Evaporation Residues

The decrease of the evaporation residue yields in reactions with massive nuclei is explained by an increase of the competition between quasifission and complete fusion processes and by the decrease of the survival probability of the heated and rotating nuclei against fission along the de-excitation cascade of the compound nucleus. The experimental data on the yields of evaporation residue, fusion-fission and quasifission fragments in the 48 Ca + 154 Sm reaction are analyzed in the framework of the combined theoretical method based on the dinuclear system concept and advanced statistical model. The measured yields of evaporation residues of the 48 Ca + 154 Sm reaction have been well reproduced and yields of fission fragments were analyzed using the partial fusion and quasifission cross sections calculated in the dinuclear system model. Such a way of calculation is used to find optimal conditions for the synthesis of the new element Z = 120 (A = 302) by studying the excitation functions of evaporation residues of the 54 Cr + 248 Cm , 58 Fe + 244 Pu , and 64 Ni + 238 U reactions. Our estimations show that the 54 Cr + 248 Cm reaction is preferable in comparison with the two others.

Fusion probability in heavy-ion collisions by a dinuclear-system model

2003 ◽  
Vol 64 (6) ◽  
pp. 750-756 ◽  
Author(s):  
W Li ◽  
N Wang ◽  
J. F Li ◽  
H Xu ◽  
W Zuo ◽  
...  
Keyword(s):  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
System Model ◽  
Dinuclear System ◽  
Ion Collisions ◽  
Fusion Probability

APPEARANCE OF FAST-FISSION AND QUASI-FISSION IN REACTIONS WITH MASSIVE NUCLEI

2005 ◽  
Vol 20 (06) ◽  
pp. 391-405 ◽  
Author(s):  
GIOVANNI FAZIO ◽  
GIORGIO GIARDINA ◽  
GIUSEPPE MANDAGLIO ◽  
FRANCIS HANAPPE ◽  
AKHTAM I. MUMINOV ◽  
...  
Keyword(s):  
Experimental Data ◽  
Reaction Mechanism ◽  
Excitation Function ◽  
Cross Sections ◽  
Neutron Emission ◽  
Evaporation Residue ◽  
Dinuclear System ◽  
Total Evaporation ◽  
Fast Fission ◽  
Evaporation Residues

The experimental data on the capture and evaporation residue cross-sections obtained in the 48 Ca +208 Pb reaction were analyzed in the framework of the dynamical model based on the dinuclear system concept and advanced statistical method to clarify the reaction mechanism. The experimental excitation function of the capture reactions was decomposed into contributions of the fusion–fission, quasifission and fast-fission processes. Total evaporation residues and ones after neutron emission were only calculated and compared with the available experimental data.

CHARMONIUM PRODUCTION IN Pb–Pb COLLISIONS AT ALICE: FROM SUPPRESSION TO REGENERATION?

2013 ◽  
Vol 28 (21) ◽  
pp. 1330018 ◽  
Author(s):  
ENRICO SCOMPARIN
Keyword(s):  
Phase Transition ◽  
Cross Sections ◽  
Short Review ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Alice Experiment ◽  
Model Calculations ◽  
Ion Collisions ◽  
Quark Production ◽  
History Of

Heavy quarkonium states are considered as one of the key observables for the study of the phase transition from a system made of hadrons towards a Quark–Gluon Plasma (QGP). In the last 25 years, experiments at CERN and Brookhaven have studied collisions of heavy ions looking for a suppression of charmonia/bottomonia, considered as a signature of the phase transition. After an introduction to the main concepts behind these studies and a short review of the SPS and RHIC results, I will describe the results obtained in Pb – Pb collisions by the ALICE experiment at the LHC. The ALICE findings will be critically compared to those of lower energy experiments, to CMS results, and to model calculations. The large cross-sections for heavy-quark production at LHC energies are expected to induce a novel production mechanism for charmonia in heavy-ion collisions, related to a recombination of [Formula: see text] pairs along the history of the collision and/or at hadronization. The occurrence of such a process at the LHC will be discussed. Finally, prospects for future measurements will be shortly addressed.

Cross sections for photons produced in the stopping phase in relativistic heavy-ion collisions

1989 ◽  
Vol 504 (4) ◽  
pp. 864-874 ◽  
Author(s):  
Joachim Thiel ◽  
Thomas Lippert ◽  
Norbert Grün ◽  
Werner Scheid
Keyword(s):  
Cross Sections ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Ion Collisions

Production cross sections of the superheavy nucleus 117 based on the dinuclear system model

2010 ◽  
Vol 34 (10) ◽  
pp. 1609-1614 ◽  
Author(s):  
Zhao Wei-Juan ◽  
Zhang Yong-Qi ◽  
Wang Hua-Lei ◽  
Song Li-Tao ◽  
Li Lu-Lu
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
Superheavy Nucleus ◽  
System Model ◽  
Dinuclear System

scholarly journals Dielectron Production in Proton–Proton Collisions at √s=7 TeV with ALICE

Proceedings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 24
Author(s):  
Sebastian Scheid
Keyword(s):  
Cross Sections ◽  
Mass Range ◽  
Heavy Ion ◽  
Event Generator ◽  
Leading Order ◽  
Proton Proton ◽  
Total Cross Sections ◽  
Proton Collisions ◽  
Ion Collisions ◽  
Proton Proton Collisions

The ALICE Collaboration measured dielectron production as a function of the invariant mass ( m ee ), the pair transverse momentum ( p T , ee ) and the pair distance of closest approach ( DCA ee ) in pp collisions at s = 7 TeV. Prompt and non-prompt dielectron sources can be separated with the DCA ee , which will give the opportunity in heavy-ion collisions to identify thermal radiation from the medium in the intermediate-mass range dominated by contributions from open-charm and beauty hadron decays. The charm and beauty total cross sections are extracted from the data by fitting the spectra with two different MC generators, i.e., PYTHIA a leading order event generator and POWHEG a next-to-leading order event generator. Significant model dependences are observed, reflecting the sensitivity of this measurement to the heavy-flavour production mechanisms.

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