Identified particle v3 measurements in 200GeV Au+Au collisions
at RHIC-PHENIX experiment
Sanshiro Mizuno for PHENIX Collaboration
University of Tsukuba

Introduction

Reaction Plane and Resolution

The particle species dependence of transverse momentum
distributions as well as elliptic event anisotropy (v2) have been
beautifully described by hydrodynamic model calculation in terms ofradial and elliptic collective expansion in high energy heavy ion
collisions. The initial participant position fluctuations has beensuggested as a source of a triangular initial geometry, which could
then expand collectively to form a final triangular event anisotropy v3
in momentum space. We present the first measurements of v3 foridentified particles at 200GeV Au+Au collisions from RHIC- PHENIX
experiment will be presented. The collective triangular expansion
behavior seen in v3 is compared with hydro-dynamic model
expectations in order to gain an understanding of possible differences,or similarities , from the radial and elliptic expansion.

Reaction Plane Calibration has 3 steps.
1. Gain correction

Data set

Q{n}x=Siwi{cos(nfi)}, Q{n}y=Siwi{sin(nfi)},F{n}=atan2(Q{n}x,Q{n}y)2. Re-Centering

Q’{n}x=Q{n}x-<Q{n}x>/sQnx, Q’{n}x=Q{n}x-<Q{n}x>/sQnx, F’{n}=atan2(Q’{n}x,Q’{n}y)3. FlatteningnF”{n}=nF’{n}+Si 2/i(-<sin(inF’{n})>cos(inF’{n})+<cos(inF’{n})>sin(inF’{n}))Measuring Resolution is needed Reaction Plane correlation.
<cos{3(FA-FB)}>RxN Out S or N
RxN Out S+N
RxN In N
RxN In+Out N

RxN Out S & RxN Out N
RxN Out S & RxN In N
RxN Out S & RxN In+Out N

RxN

PHENIX Run7 Au+Au 200GeV
Centrality 20-50%

Fig.1 Reaction Plane correlation and Resolution of Reaction PlaneMethod

CNT(reaction plane detector)(PHENIX Central Arm)

Particle identification

TOF.E

When selecting particle species (p, K, p) particle identification is used
via time of flight measurements.

v2 and v3 are measured using function.
vn,observed = <cos{n(Fn,particle-Fn,Reaction Plane)}>hvn,real = vn,observed / Res(Fn,Reaction Plane)vn,observed : observed vn , Fn,particle : azimuthal angle of particle
Fn,Reaction Plane : azimuthal angle of Reaction Planevn,real : real vn
Calculating Reaction Plane and Resolution is needed for measuring
v2 and v3.

p+pK+p- K-p-bar

Fig.2 Mass distribution on TOF.E

Results
Triangular flow in hydrodynamics
and transport theory[5]Fig.5 KET dependence of nquark
Fig.3 pT dependence of Identified Fig.4 pT dependence of nquark
scaling Identified particle v2
scaling Identified particle v2particle v222KET  m0 + pT - m0
Dependence is similar to meson(p and K) and baryon(p)v3

pT[GeV/c]

Fig.6 Differential triangular flow for
identified particles in central(0-5%) Au-Au collisions at RHIC

Fig.7 pT dependence of Identified Fig.8 pT dependence of nquark
Fig.9 KET dependence of nquarkparticle v3
scaling Identified particle v3
scaling Identified particle v3
Identified particle v3 as function of pT was measured.
Triangular anisotropy has a particle species dependence.
v2 and v3 of nquark scaling was measured.
It seems that KET of nquark scaling v2 is more overlap, and pT of nquark scaling v3 is more overlap.
Using Run7 full statistics (to come) will enable, our analysis uses 1% of it.
Study finer centrality dependence.
Measure deuteron and other particle dependence.

[5]Burak Han Alver, arXiv:1007.5469[nucl-th]ConclusionandOutlook

KET/nquark=