skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Charged Hadron Multiplicity Fluctuations in Au+Au and Cu+Cu Collisions from s_NN = 22.5 to 200 GeV

Journal Article · · Physical Review C
 [1];  [2];  [2];  [3];  [2];  [2];  [4];  [2];  [2]
  1. University of Colorado, Boulder
  2. ORNL
  3. University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)
  4. University of Tennessee, Knoxville (UTK)

A comprehensive survey of event-by-event fluctuations of charged hadron multiplicity in relativistic heavy ions is presented. The survey covers Au+Au collisions at {radical}s{sub NN} = 62.4 and 200 GeV, and Cu+Cu collisions at {radical}s{sub NN} = 22.5,62.4, and 200 GeV. Fluctuations are measured as a function of collision centrality, transverse momentum range, and charge sign. After correcting for nondynamical fluctuations due to fluctuations in the collision geometry within a centrality bin, the remaining dynamical fluctuations expressed as the variance normalized by the mean tend to decrease with increasing centrality. The dynamical fluctuations are consistent with or below the expectation from a superposition of participant nucleon-nucleon collisions based upon p+p data, indicating that this dataset does not exhibit evidence of critical behavior in terms of the compressibility of the system. A comparison of the data with a model where hadrons are independently emitted from a number of hadron clusters suggests that the mean number of hadrons per cluster is small in heavy ion collisions.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
DOE Contract Number:
DE-AC05-00OR22725
OSTI ID:
950431
Journal Information:
Physical Review C, Vol. 78, Issue 4
Country of Publication:
United States
Language:
English