Influence of the impact parameter on element distributions in dissipative heavy-ion collisions

1982 ◽  
Vol 25 (1) ◽  
pp. 338-349 ◽  
Author(s):  
H. J. Wollersheim ◽  
W. W. Wilcke ◽  
J. R. Birkelund ◽  
J. R. Huizenga
2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Gao-Feng Wei ◽  
Guo-Qiang He ◽  
Xin-Wei Cao ◽  
Yi-Xin Lu

The impact parameter dependence ofπ-/π+ratio is examined in heavy-ion collisions at 400 MeV/nucleon within a transport model. It is shown that the sensitivity ofπ-/π+ratio on symmetry energy shows a transition from central to peripheral collisions; that is, the stiffer symmetry energy leads to a largerπ-/π+ratio in peripheral collisions while the softer symmetry energy always leads this ratio to be larger in central collisions. After checking the kinematic energy distribution ofπ-/π+ratio, we found this transition of sensitivity ofπ-/π+ratio to symmetry energy is mainly from less energetic pions; that is, the softer symmetry energy gets the less energetic pions to form a smallerπ-/π+ratio in peripheral collisions while these pions generate a largerπ-/π+ratio in central collisions. Undoubtedly, the softer symmetry energy can also lead more energetic pions to form a largerπ-/π+ratio in peripheral collisions. Nevertheless, considering that most of pions are insufficiently energetic at this beam energy, we therefore suggest theπ-/π+ratio as a probe of the high-density symmetry energy effective only in central at most to midcentral collisions, thereby avoiding the possible information of low-density symmetry energy carried inπ-/π+ratio from peripheral collisions.


2019 ◽  
Vol 223 ◽  
pp. 01050
Author(s):  
Silvia Piantelli ◽  
Alessandro Olmi ◽  
Paolo R. Maurenzig ◽  
Akira Ono ◽  
Maurizio Bini ◽  
...  

The simulation of heavy ion collisions in the Fermi energy region is a challenge for the theoretical models; in particular it is difficult to obtain a coherent description in all the impact parameter range and to reproduce all the experimental observables. In this contribution we will show the very good job done by the dynamical model AMD [1] followed by the statistical code GEMINI [2, 3] as an afterburner. The model is able to reproduce the main characteristics of peripheral and semiperipheral collisions, although some discrepancies still persist.


1994 ◽  
Vol 107 (5) ◽  
pp. 697-711
Author(s):  
A. Del Zoppo ◽  
C. Agodi ◽  
R. Alba ◽  
G. Bellia ◽  
R. Coniglione ◽  
...  

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Hongxi Xing ◽  
Cheng Zhang ◽  
Jian Zhou ◽  
Ya-Jin Zhou

Abstract We present a detailed study of vector meson photoproduction in ultraperipheral heavy ion collisions (UPCs). Using the dipole model, we develop a framework for the joint impact parameter and transverse momentum dependent cross sections. We compute the unpolarized cross section and cos 2ϕ azimuthal angular correlation for ρ0 photoproduction with ϕ defined as the angle between the ρ0’s transverse momentum and its decay product pion meson’s transverse momentum. Our result on unpolarized coherent differential cross section gives excellent description to the STAR experimental data. A first compari- son between theoretical calculation and experimental measurement on the cos 2ϕ azimuthal asymmetry, which results from the linearly polarized photons, is performed and reasonable agreement is reached. We find out the characteristic diffractive patterns at both RHIC and LHC energies and predict the impact parameter dependent cos 2ϕ azimuthal asymmetries for ρ0 photoproduction by considering UPCs and peripheral collisions. The future experimental measurements at RHIC and LHC relevant to our calculations will provide a tool to rigorously investigate the coherent and incoherent production of vector meson in UPCs, as well as to probe the nuclear structure in heavy ion collisions.


Particles ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 275-287
Author(s):  
Petr Parfenov ◽  
Dim Idrisov ◽  
Vinh Ba Luong ◽  
Arkadiy Taranenko

The size and evolution of the matter created in relativistic heavy-ion collisions strongly depend on collision geometry, defined by the impact parameter. However, the impact parameter cannot be measured directly in an experiment but might be inferred from final state observables using the centrality procedure. We present the procedure of centrality determination for the Multi-Purpose Detector (MPD) at the NICA collider and its performance using the multiplicity of produced charged particles at midrapidity. The validity of the procedure is assessed using the simulated data for Au + Au collisions at sNN = 4–11 GeV.


1992 ◽  
Vol 69 (10) ◽  
pp. 1504-1507 ◽  
Author(s):  
S. Riess ◽  
G. Enders ◽  
A. Hofmann ◽  
W. Kühn ◽  
V. Metag ◽  
...  

2021 ◽  
Vol 103 (9) ◽  
Author(s):  
Neelkamal Mallick ◽  
Sushanta Tripathy ◽  
Aditya Nath Mishra ◽  
Suman Deb ◽  
Raghunath Sahoo

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