A New method for measuring azimuthal distributions in nucleus-nucleus collisions

Jul, 2000
33 pages
Published in:
  • Phys.Rev.C 63 (2001) 054906
e-Print:
Report number:
  • SACLAY-SPH-T-00-110

Citations per year

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Abstract:
The methods currently used to measure azimuthal distributions of particles in heavy ion collisions assume that all azimuthal correlations between particles result from their correlation with the reaction plane. However, other correlations exist, and it is safe to neglect them only if azimuthal anisotropies are much larger than 1/sqrt(N), with N the total number of particles emitted in the collision. This condition is not satisfied at ultrarelativistic energies. We propose a new method, based on a cumulant expansion of multiparticle azimuthal correlations, which allows to measure much smaller values of azimuthal anisotropies, down to 1/N. It is simple to implement and can be used to measure both integrated and differential flow. Furthermore, this method automatically eliminates the major systematic errors, which are due to azimuthal asymmetries in the detector acceptance.
  • scattering: heavy ion
  • multiple production: particle flow
  • angular distribution: anisotropy
  • angular correlation
  • cumulant expansion
  • statistical analysis
  • correction: acceptance
  • data analysis method: proposed
  • numerical calculations: Monte Carlo