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K/pi Fluctuations at relativistic energies
B I Abelev1, M M Aggarwal, Z Ahammed
1Argonne National Laboratory, Argonne, Illinois 60439, USA.
Physical Review Letters
|October 2, 2009
Summary
We studied kaon to pion (K/pi) fluctuations in gold-gold collisions across various energies. Results show K/pi fluctuations are largely independent of energy and scale with particle density.
Area of Science:
- Nuclear Physics
- High-Energy Physics
- Particle Physics
Background:
- Understanding particle production in heavy-ion collisions is crucial for probing the properties of nuclear matter.
- Kaon to pion (K/pi) ratios and their fluctuations offer insights into the dynamics of the quark-gluon plasma.
Purpose of the Study:
- To investigate K/pi fluctuations in gold-gold (Au + Au) collisions at various incident energies using the STAR detector.
- To examine the dependence of K/pi fluctuations on collision centrality and incident energy.
- To compare results with existing data from other experiments.
Main Methods:
- Analysis of Au + Au collision data collected by the STAR detector at the Relativistic Heavy Ion Collider (RHIC).
- Measurements performed at center-of-mass energies per nucleon pair (sqrt[s(NN)]) of 19.6, 62.4, 130, and 200 GeV.
- Investigation of collision centrality dependence and charge-separated K/pi fluctuations.
Main Results:
- K/pi fluctuations in central collisions exhibit minimal dependence on incident energy across the studied RHIC energies.
- The magnitude of K/pi fluctuations is comparable to that observed in lead-lead (Pb + Pb) collisions at lower energies (Super Proton Synchrotron - SPS).
- K/pi fluctuations demonstrate a clear scaling behavior with the charged particle multiplicity density.
Conclusions:
- The observed energy independence of K/pi fluctuations suggests a consistent dynamical behavior in central heavy-ion collisions within the studied energy range.
- Scaling with charged particle multiplicity provides a key observable for understanding particle production mechanisms.
- These findings contribute to the broader understanding of matter under extreme conditions at RHIC.
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