HBT and collective flow at mid-rapidity in $d$$+$Au collisions

May 21, 2014, 12:30 PM
europium (darmstadtium)



Schlossgraben 1 64283 Darmstadt Germany
Contributed Talk Collective Dynamics Correlations and fluctuations


Nuggehalli AJITANAND (Stony Brook University)


Recent results obtained at RHIC and the LHC have revealed the presence of unexpected collective effects in central $p(d)$$+$A collisions. Different techniques and physical observables have been utilized to understand whether these collective effects have a similar origin to heavy ion collisions or can be explained solely by cold nuclear matter effects. Two-pion Bose-Einstein correlation is a valuable tool for studying the space-time extent of emission sources in $p(d)$$+$A and A$+$A interactions, while the measurement of the charged particle momentum anisotropy helps in understanding of the collision collective dynamics. In this talk we report new PHENIX results for these observables. PHENIX has extracted the 3D HBT radii as a function of centrality and transverse-pair momentum ($k_T$), for the $d$$+$Au and Au$+$Au collision systems. A comparison of the radii for both systems indicate strong similarities in the detailed dependencies on centrality and $k_T$, suggestive of important final-state rescattering effects in the reaction dynamics for the $d$$+$Au and Au$+$Au systems. The measurements also point to a smaller freeze-out size and system lifetime in $d$$+$Au as compared to Au$+$Au. We also report recent PHENIX results for elliptic flow measured for charged hadrons near midrapidity in $d$$+$Au collisions that complement recent analyses by experiments at the LHC. We observe qualitatively similar, but larger, anisotropies in $d$$+$Au collisions compared to those seen in $p$$+$Pb collisions at the LHC that is consistent with expectations from hydrodynamic calculations owing to the larger expected initial-state eccentricity. The combined HBT and flow data provide significant constraints on hydrodynamic and glasma diagram explanations.
On behalf of collaboration: PHENIX

Primary author

Nuggehalli AJITANAND (Stony Brook University)

Presentation materials