May 13 – 19, 2018
Venice, Italy
Europe/Zurich timezone
The organisers warmly thank all participants for such a lively QM2018! See you in China in 2019!

PHENIX measurement of J/psi polarization via decay di-electron pairs produced in p+p collisions at sqrt(s) = 510 GeV at mid-rapidity

May 15, 2018, 5:00 PM
2h 40m
First floor and third floor (Palazzo del Casinò)

First floor and third floor

Palazzo del Casinò

Poster Chirality, vorticity and polarisation effects Poster Session


Sookhyun Lee (Iowa State University)


Heavy quarkonia in high-energy collisions is a sensitive probe of Quantum Chromo Dynamics (QCD) due to its large scale provided by the heavy quark mass relative to the hadronization scale. The angular distribution of decay leptons from heavy quark bound state is a key observable to test heavy quarkonia production mechanisms and bound state formation. Charmonium, in particlular, is an essential tool as it decays into di-leptons with a large branching ratio. PHENIX and STAR have observed J/$\psi$ polarization consistent to zero within uncertainties with limited statistics via measurements of polar angular distribution in decay di-electron pairs at $\sqrt{s}$ = 200 GeV at midrapidity. Recently, measurement of full (polar and azimuthal) angular distribution from J/psi decay to di-muon pairs at $\sqrt{s}$=510 GeV in the forward rapidity region has shown good agreement with predictions made by non-relativistic QCD at high pT and disagreement at low pT, posing a challenge to this theoretical approach. This poster will present the status of data analysis underway on the data taken from p+p collisions at $\sqrt{s}$=510 GeV in 2013 at RHIC. This new measurement of J/psi polarization via full angular distribution from J/$\psi$ decays to di-electrons at mid-rapidity $|y|<$0.35 at this higher energy will bring new insights into charmonium production and hadronization process.

Content type Experiment
Collaboration PHENIX
Centralised submission by Collaboration Presenter name already specified

Primary author

Sookhyun Lee (Iowa State University)

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