# Beam-energy and system-size dependence of the space-time extent of the pion emission source produced in heavy ion collisions

Abstract : Two-pion interferometry measurements are used to extract the Gaussian radii $R_{{\rm out}}$, $R_{{\rm side}}$, and $R_{{\rm long}}$, of the pion emission sources produced in Cu$+$Cu and Au$+$Au collisions at several beam collision energies $\sqrt{s_{_{NN}}}$ at PHENIX. The extracted radii, which are compared to recent STAR and ALICE data, show characteristic scaling patterns as a function of the initial transverse size $\bar{R}$ of the collision systems and the transverse mass $m_T$ of the emitted pion pairs, consistent with hydrodynamiclike expansion. Specific combinations of the three-dimensional radii that are sensitive to the medium expansion velocity and lifetime, and the pion emission time duration show nonmonotonic $\sqrt{s_{_{NN}}}$ dependencies. The nonmonotonic behaviors exhibited by these quantities point to a softening of the equation of state that may coincide with the critical end point in the phase diagram for nuclear matter.
Document type :
Preprints, Working Papers, ...

http://hal.in2p3.fr/in2p3-01073614
Contributor : Dominique Girod Connect in order to contact the contributor
Submitted on : Friday, October 10, 2014 - 10:47:24 AM
Last modification on : Tuesday, January 5, 2021 - 9:30:19 AM

### Identifiers

• HAL Id : in2p3-01073614, version 1
• ARXIV : 1410.2559

### Citation

A. Adare, Laurent Aphecetche, E. T. Atomssa, H. Delagrange, O. Drapier, et al.. Beam-energy and system-size dependence of the space-time extent of the pion emission source produced in heavy ion collisions. 2014. ⟨in2p3-01073614⟩

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