Energy Dependence of $K\ddot{I}€$, $p\ddot{I}€$, and $Kp$ Fluctuations in Au+Au Collisions from $\sqrt{{\mathrm{s}}_{\mathrm{NN}}}$ = 7.7 to 200 GeV

Abstract

A search for the quantum chromodynamics (QCD) critical point was performed by the STAR experiment at the Relativistic Heavy Ion Collider, using dynamical fluctuations of unlike particle pairs. Heavy-ion collisions were studied over a large range of collision energies with homogeneous acceptance and excellent particle identification, covering a significant range in the QCD phase diagram where a critical point may be located. Dynamical $K\ddot{I}€$, $p\ddot{I}€$, and $Kp$ fluctuations as measured by the STAR experiment in central 0-5\% Au+Au collisions from center-of-mass collision energies $\sqrt{{\mathrm{s}}_{\mathrm{NN}}}$ = 7.7 to 200 GeV are presented. The observable $\hat{\mathrm{I}}{½}_{\mathrm{dyn}}$ was used to quantify the magnitude of the dynamical fluctuations in event-by-event measurements of the $K\ddot{I}€$, $p\ddot{I}€$, and $Kp$ pairs. The energy dependences of these fluctuations from central 0-5\% Au+Au collisions all demonstrate a smooth evolution with collision energy.

7 pages, 3 figures