190 likes | 207 Views
PHENIX Measurements of Higher-order Flow Harmonics for Identified Charged Hadrons in Au+Au Collisions at = 39 – 200 GeV. Yi Gu (for PHENIX Collaboration ) Nuclear Chemistry Group SUNY Stony Brook. Yi Gu ( for PHENIX collaboration) Stony Brook University.
E N D
PHENIX Measurements of Higher-order Flow Harmonics for Identified Charged Hadrons in Au+Au Collisions at = 39 – 200 GeV Yi Gu (for PHENIX Collaboration ) Nuclear Chemistry Group SUNY Stony Brook Yi Gu ( for PHENIX collaboration) Stony Brook University Quark Matter 2012, Washington D.C, Aug 14th,2012
Outline • The Flow Probe • Utility as constraints for transport coefficients extraction • PHENIX Detector • Advantages for flow measurements • New PHENIX results • Identified charged hadron v2, v3 , v4 at = 200 GeV • Energy dependence of PIDed v2 , v3 at = 39 – 200 GeV • Scaling properties of flow results • Discussion & comparison with LHC data • Conclusion and Summary Quark Matter 2012, Washington D.C, Aug 14th,2012
The Flow Probe ε2 • Initial spatial fluctuations of nucleons result in higher moments of deformations, each with its own orientation. Alver, Roland, Staig, Shuryak, ε3 ε4 Odd harmonics = 0 ε2 Odd harmonics ≠ 0 Quark Matter 2012, Washington D.C, Aug 14th,2012
Flow as a constraint for η/s • Systematic measurements of vn as a function of centrality, pT, beam energy, particle species, etc are crucial for further constraining η/s via model comparisons • Higher order harmonics (v3, v4, etc) provide constraints on the interplay of initial geometry and shear viscosity. Phys. Rev. Lett. 107, 252301 (2011) Quark Matter 2012, Washington D.C, Aug 14th,2012
Flow Measurement in PHENIX Wide range of coverage with several RxNP. detectors ψn RXN (|η|=1.0~2.8) MPC (|η|=3.1~3.7) BBC (|η|=3.1~3.9) Event Plane technique with systemic studies using various event plane detectors Pair-wise azimuthal angle correlation technique (2PC technique )correlating tracks from central arm and from various event plane detectors Quark Matter 2012, Washington D.C, Aug 14th,2012
v2 , v3, v4 at 200 GeV for Identified charged hadrons • New detailed studies of particle identified flow at 200GeV with substantial reduction of sys. & stat. uncertainties • Consistent results for 2PC with sizeable ∆η and EP methods Quark Matter 2012, Washington D.C, Aug 14th,2012
v2 , v3, v4 at 200 GeV for Identified charged hadrons Quark Matter 2012, Washington D.C, Aug 14th,2012
Energy dependence of PIDed v2 , v3 at 39 – 200 GeV • New measurements of particle identified v3 from 2010 low energies runs • No sizeable beam energy dependence observed for v2 and v3 for each particle species • Implies flow saturates for 39-200 GeV Quark Matter 2012, Washington D.C, Aug 14th,2012
Energy Dependence of vn for charged hadrons • Charge hadron results for v2, v3 and v4 consistent with saturation of identified charged particles vn for beam energies of 39-200GeV Quark Matter 2012, Washington D.C, Aug 14th,2012
Comparison of charged hadron vn @ RHIC & LHC RHIC Au+Au √s = 0.2 TeV LHC Pb+Pb √s = 2.76 TeV arxiv: 1207.1886, Roy lacey, Yi Gu, et.al • Similar vn results observed from 0.039 - 2.76TeV for charged hadrons Quark Matter 2012, Washington D.C, Aug 14th,2012
Comparison of charged hadron vn @ RHIC & LHC Does flow actually saturate? • Multiplicity-weighted PIDed flow results reproduce inclusive charged hadron flow results at RHIC and LHC respectively • Energy density increases by a factor of 3 from RHIC to LHC Quark Matter 2012, Washington D.C, Aug 14th,2012
Comparison with LHC PIDed v2 , v3 … arxiv: 1207.1886, Roy lacey, Yi Gu, et.al • There is energy density dependence from RHIC to LHC. Larger energy densities at LHC results in stronger flow • v2 of each particle species all show ~20% difference from LHC particle identified flow results, in 20-30% centrality slice • Blue shift(velocity shift) for protons • Similar quick check indicates v3 also deviate by similar amount from LHC data • Flow does NOT saturate from RHIC to LHC Quark Matter 2012, Washington D.C, Aug 14th,2012
Scaling Properties of Flow Resultsat 200 GeV • NCQ-scaling holds well for v2,v3,v4 below 1GeV in KET space, at 200GeV ->Partonic flow Quark Matter 2012, Washington D.C, Aug 14th,2012
Scaling Properties of Flow Resultsat 39, 62.4 GeV • Within uncertainties, NCQ-scaling holds below 1GeV in KET space, at 39 , 62.4GeV. Shengli Huang’s parallel talk on Deviation from quark number scaling of the anisotropy parameter in Au+Au collisions Quark Matter 2012, Washington D.C, Aug 14th,2012
Summary • Comprehensive new measurements of particle identified higher order event anisotropy made at 39, 62.4 and 200GeV • vn extracted via both EP and 2PC methods • vn for identified charged hadron saturates for the beam energy range of 39-200GeV • Consistent with observed saturation for charged hadrons • Inconsistent with a saturation of vn from RHIC to LHC implied by charged hadron measurements • NCQ scaling of vn for identified charged hadrons observed for the beam energy range of 39–200 GeV • Further confirm the flow is partonic at low beam energies • These new measurements provide additional constraints for extraction of transport coefficients Quark Matter 2012, Washington D.C, Aug 14th,2012
Thank you Quark Matter 2012, Washington D.C, Aug 24th,2012
R.P detectors Resolutions • Correlate hadrons in central arms |η|<0.35with event plane (RXN, etc ), corrected by its dispersion reference to reaction plane(Resolution) Multiple R.P detectors with large coverage ->consistency check and non-flow effect studies • (2nd order) RXN has the best resolution at each beam energy • Resolution drops dramatically as collision goes to more peripheral or central Workshop on Fluctuations, Correlations and RHIC Low Energy Runs , BNL, Oct 3rd,2011