A Centrality Detector Concept

Abstract

The nucleus-nucleus impact parameter and collision geometry of a heavy ion collision are typically characterized by assigning a collision "centrality". In all present heavy ion experiments centrality is measured indirectly, by detecting the number of particles or the energy of the particles produced in the interactions, typically at high rapidity. Centrality parameters are associated to the measured detector response using the Glauber model. This approach suffers from systematic uncertainties related to the assumptions about the particle production mechanism and limitations of the Glauber model. In the collider based experiments there is a unique possibility to measure centrality parameters by registering spectator fragments remaining from the collision. This approach does not require model assumptions and relies on the fact that spectators and participants are related via the total number of nucleons in the colliding species. This article describes the concept of the centrality detector for heavy ion experiment, which measures the total mass number of all fragments by measuring their deflection in the magnetic field of the collider elements.

19 pages, 11 figures

References in corpus (4)

• Glauber Modeling in High Energy Nuclear Collisions
• Phobos results on charged particle multiplicity and pseudorapidity distributions in Au+Au, Cu+Cu, d+Au, and p+p collisions at ultra-relativistic energies
• The PHOBOS Glauber Monte Carlo
• Rapidity Spectra of the Secondaries Produced in Heavy Ion Collisions and the Constituent Picture of the Particles

Cited by in corpus (2)

• Neutron skin and centrality classification in high-energy heavy-ion collisions at the LHC
• Using LHC Forward Proton Detectors to Tag Nuclear Debris