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Recent Quarkonia Results from PHENIX. Abhisek Sen , Georgia State University for the PHENIX collaboration. Probing the medium with Quarkonia. Quarkonium dissociation is suggested as a thermometer for the medium created at heavy ion collisions.
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Recent Quarkonia Results from PHENIX AbhisekSen, Georgia State University for the PHENIX collaboration
Probing the medium with Quarkonia • Quarkonium dissociation is suggested as a thermometer for the medium created at heavy ion collisions. • Highlights of recent quarkonia results from PHENIX • J/ψ feed down measurement (p+p). • d+Au CNM reference at 200 GeV. • J/ψ measurement from Au+Au at 200 , 62 & 39 GeV. • Upsilon measurements (p+p and d+Au). Mocsy & Petreczky PRL. 99, 211602 (2007)
Di-leptons in p+p Midrapidity |y|<0.35 Forward Rapidity 1.2 < |y| <2.2 PHENIX has excellent capabilities of measuring different quarkonia states in di-electron and di-muon channels.
J/ψproduction at p+p PRL 98, 232002 (2007) Total J/ψ cross-section : 181 +/- 22 nb (stat. + sys.) ArXiv: 1105.1966v1
J/yfeed down measurement c→J/y+ y’→ e+e- = 9.6 +/- 2.4% ArXiv: 1105.1966v1 = 32 +/- 9 %
J/ψsuppression in Au+Au 200 GeV New forward data from 2007 with finer binning and lower systematics. Total J/ψfeed-down : 42 +/- 9 % An extreme case : Enough temperature to melt ψ’ and Caccording to lattice calculations. Npart arXiv: 1103:6269
J/ψsuppression in Au+Au 200 GeV Historic Puzzle Suppression is stronger at forward rapidity than mid-rapidity. NA50, 17.2 GeV Suppression in mid-rapidity is comparable to that measured at SPS energies. No obvious pattern of the suppression with energy density. arXiv: 1103:6269
Probing Cold Nuclear Matter Effects LO • PHENIX can probe all Bjorken x range where EPS09 predicts • Suppression at shadowing region. • Suppression-enhancement transition • Enhancement at anti-shadowing region. d Au PHENIX high statistics d+Au dataset from 2008 is now analyzed.
J/ψsuppression in d+Au Geometry integrated EPS09 is in agreement with geometry integrated (MB) data. • (Solid red curves) A reasonable agreement with EPS09 nPDF + sbr = 4 mb for central collisions but not peripheral. • (Dashed green line) CGC calculations can’t reproduce mid-rapidity. (Nucl. Phys. A 770(2006) 40) • (Solid Red curves) A reasonable aggreement with EPS09 nPDF + sbr = 4 mb . • (Dashed green line) CGC calculations can’t reproduce mid-rapidity. (Nucl. Phys. A 770(2006) 40) y What about RCP ? EPS09 with assumed linear thickness dependence fails to describe centrality dependence of forward rapidity region. Lets arbitrarily give EPS09 a linear geometry dependence arxiv:1010.1246
d+Au Geometry dependence Nuclear geometry via density-weighted longitudinal thickness Woods-Saxon • Break-up has exponential dependence. • EPS09 has unknown dependence.
RdAuwith geometry For any value of a, we can put a point in the RCP(a) - RdAu(a) plane. Ellipses are systematic uncertainties. The forward rapidity points suggests a quadratic or higher geometry dependence.
New pT dependence ofRdAu • RdAu at midrapidity |y|<0.35. • Convoluted shadowing + Cronin effect. • Proper geometry dependence of shadowing needed. See Darren McGlinchey’s Poster
Energy dependence of J/ψproduction for Au+Au.
New: J/ψfrom Au+Au 62 and 39 GeV In 2010 PHENIX collected 700M (200M) MB events from 62.4 GeV (39 GeV) Au+Au collision. Rapidity 1.2 <|y| <2.2
Energy dependence of J/ψRCP Rapidity 1.2 <|y| <2.2 • PHENIX doesn’t have a p+p reference at 62 and 39 GeV. • RCP will give us an insight about the suppression level. • Suppression is of similar level at all energies. • Accounting for energy dependence of CNMs is critical for interpreting these results.
Energy dependence of CNMs A systematic analysis at y~0 using EKS98 + σbreakup showed a clear collision energy dependence of σbreakup. RG for J/ψ production at RHIC 1.2 < y < 2.2 |y| < 0.35 -2.2 < y < -1.2 JHEP 0902:014 (2009) • Proper geometry dependence need to be included. • Reduce uncertainties by measuring d+Au • at the same energy.
’s in p+p collisions at 200 GeV 1.2 < |y| <2.2 -2.2 < y <-1.2 |y|<0.35
New PHENIX results d+Au Au+Au d Au RAA Coming soon! Coming soon RdAu at mid-rapidity First measurement of CNM effects in production at RHIC.
Summary • Total J/y feed down from y’ and C at 200 GeV at midrapidity is 42 +/- 9% in p+p. • CNM effects are a large fraction of the observed Au+Au suppression and extrapolation from d+Au to Au+Au is imperative. • Geometry dependence of shadowing is stronger than linear. • Measured Au+Au J/y suppression at 200, 62 and 39 GeV. • Measured upsilon suppression in d+Au collisions.
Model comparison arXiv: 1103:6269 Projection of EPS09 shadowing and sbr to Au+Au collision in mid-rapidity and forward-rapidity doesn’t reproduce RAA or the ratio between rapidities. Combine x-dependent nuclear absorption (but sbr=0 at midrapidity) with hot, dissociative comoving medium (sco=0.65mb).
Cold nuclear matter effects(CNM) • Need to understand nuclear affects without any hot medium( a.k.a CNM). • J/ψfrom p+Au or d+Au is a excellent probe to understand this effects. • Nuclear PDFs known to be modified at various x ranges. • shadowing, anti-shadowing, EMC effects etc. • PHENIX can probe both shadowing and anti-shadowing region with detectors at • forward y, x~0.005 • mid y, x~0.03 • backward y, x~0.1 anti-shadowing • (Solid Red curves) A reasonable aggreement with EPS09 nPDF + sbr = 4 mb . • (Dashed green line) CGC calculations by Kharzeev and Tuchin (Nucl. Phys. A 770(2006) 40), includes gluon saturation at low x explains forward rapidity. d Au shadowing K.J. Eskola et al. Nucl. Phys. B535 (1998) 351
Available Data Sets A collection of Selected results Forward Weekly Meeting
PHENIX detector configurations • Central arms: • Hadrons, photons, electrons • J/y→ e+e-;y’ → e+e-; • c→ e+e-; • |η|<0.35 • pe > 0.2 GeV/c • Δφ=π(2 arms x π/2) • Forward rapidity arms: • Muons • J/y→ μ+μ-; → μ+μ- • 1.2<|η|<2.2 • pμ > 1 GeV/c • Δφ = 2π RPC1