Abstract
Determining the centrality of a collision, or the impact parameter, in heavy-nucleus collisions is important for the analysis of all experimental data and their comparison with theory. One of the methods for this is to measure the number of spectators using a hadron calorimeter arranged at a small angle to the nuclear beam. It is shown that the accuracy in determining the impact parameter at the attainable energy resolution of the hadron calorimeter is inadequate for using the calorimeter in the MPD/NICA and CBM/FAIR projects. The error is as large as 35% at the beam energy of 2.5 GeV even for peripheral collisions. Secondary processes during the motion of spectators through a nucleus make an additional contribution to the error for central and mid-central collisions.
Similar content being viewed by others
REFERENCES
M. Luzum and P. Romatschke, Phys. Rev. C 78, 034915 (2008); arXiv: 0804.4015 [nucl-th].
ALICE Collab., Phys. Rev. C 88, 044909 (2013); arXiv: 1301.4361 [nucl-ex].
ALICE Collab., J. High Energy Phys. 1807, 103 (2018); arXiv: 1804.02944 [nucl-ex].
ALICE Collab., Phys. Rev. Lett. 116, 132302 (2016); arXiv: 1602.01119 [nucl-ex].
ALICE Collab., Phys.Lett. B 772, 567 (2017); arXiv: 1612.08966 [nucl-ex].
A. Ivashkin et al., EPJ Web Conf. 204, 07002 (2019).
A. Kurepin, A. Litvinenko, and E. Litvinenko, EPJ Web Conf. 204, 03014 (2019); arXiv:1901.06508 [nucl-ex].
D. Hudson, Statistics Lectures on Elementary Statistics and Probability (CERN, Geneva, 1964).
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
The authors declare that they have no conflicts of interest.
Additional information
Translated by M. Potapov
Rights and permissions
About this article
Cite this article
Kurepin, A.B., Litvinenko, A.G. & Litvinenko, E.I. Determining the Centrality of a Nuclear Collision Using a Hadron Calorimeter. Phys. Atom. Nuclei 83, 1359–1362 (2020). https://doi.org/10.1134/S106377882009015X
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S106377882009015X