Speaker
Nuggehalli AJITANAND
(Stony Brook University)
Description
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)
