1 / 13

Meson and Baryon Elliptic Flow in Au+Au Collisions

Investigating identified hadron elliptic flow patterns in Au+Au collisions at √sNN = 200 GeV, with a focus on pion, kaon, proton, and deuteron flow characteristics.

georgedavis
Download Presentation

Meson and Baryon Elliptic Flow in Au+Au Collisions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Elliptic flow of identified hadrons (/K/p/d) in Au + Au collisions at sNN = 200 GeV Hiroshi Masui for the PHENIX collaboration Hiroshi Masui University of Tsukuba

  2. Outline • Introduction • v2(pT) of identified hadrons • /K/p • Centrality dependence • Quark Coalescence picture • Deuteron v2. • Summary Hiroshi Masui University of Tsukuba

  3. Azimuthal anisotropy - Elliptic flow (v2) - Y • Sensitive probe for early stage of heavy ion collisions. • Initial asymmetry in coordinate space  final asymmetry in momentum space. X Py v2 = <cos2>  = tan-1(py/px) Px Hiroshi Masui University of Tsukuba

  4. Analysis methodReaction plane analysis  : azimuthal angle of charged particles  : azimuthal angle of reaction plane v2 : strength of elliptic flow pattern Target Projectile Reaction plane b:impact parameter Hiroshi Masui University of Tsukuba

  5. Reaction plane determination • Reaction plane is determined at BBC (3<||<4). • 3 units of rapidity away from the mid-rapidity. Less non-flow contribution  : azimuthal location of each PMT w : weight  : azimtuthal angle of reaction plane Hiroshi Masui University of Tsukuba

  6. Hadron identification • Time of flight •  = /8, || < 0.35 • Timing resolution TOF ~ 115 ps • PID in m2 vs momentum space •  : 0.2 < pT < 3.0 GeV/c • K : 0.4 < pT < 3.0 GeV/c • P : 0.6 < pT < 4.0 GeV/c Hiroshi Masui University of Tsukuba

  7. v2(pT) of identified hadrons Minimum bias sNN = 200 GeV • pT < 2.0 GeV/c • v2() > v2(K) > v2(p) • Consistent with calculation of hydrodynamical model. • pT > 2.0 GeV/c • v2(p) > v2(), v2(K) • Clear departure from hydrodynamical behavior is observed. • Saturation at intermediate pT. Hiroshi Masui University of Tsukuba

  8. Centrality dependence of v2(pT) • Same trend can be seen in all centrality bins. • v2(baryon) > v2(meson) @ intermediate pT. Hiroshi Masui University of Tsukuba

  9. Model predictionQuark Coalescence Model D. Molnar, S.A. Voloshin, nucl-th/0302014 Hiroshi Masui University of Tsukuba

  10. Quark Coalescence picture • Scaled by the number of constituent quarks. • v2 v2/nquark • pT  pT/nquark • Remove mass dependence @ intermediate pT. • Mass dependence @ low pT. • Hydro.,  feed down. More studies are needed @ higher pT. Minimum bias sNN = 200 GeV Hiroshi Masui University of Tsukuba

  11. Deuteron v2(pT) PHENIX PRELIMINARY PHENIX PRELIMINARY • v2(/K/p) > v2(d) at pT = 1 – 2 GeV/c. Quark Coalescence works for d, dbar • But statistical error is too large. Need more statistics. Minimum bias sNN = 200 GeV Hiroshi Masui University of Tsukuba

  12. High pT upgrade @ PHENIX Integration Volume PMT Aerogel (11x22x11 cm^3) • Aerogel Cherenkov Counter (n=1.0114) • Aerogel together with TOF can extend the PID capability up to 10 GeV/c !. 160 Cells PMT Rφ Ｚ Hiroshi Masui University of Tsukuba

  13. Summary • Elliptic flow (v2) of identified hadrons (/K/p/d) has been measured at PHENIX. • Different behavior for different particle species. • Consistent with hydrodynamical model (pT < 2.0 GeV/c). • Deviate hydro. and saturation (pT > 2.0 GeV/c). • Qualitatively agreement with Quark Coalescence scenario in intermediate pT region. • An indication that v2 of measured hadrons is already established in a quark-matter phase. • Higher pT data will be available in the next Run. • Detailed study at intermediate to high pT region. Hiroshi Masui University of Tsukuba

More Related