Speaker
Description
While the study of charmonium production provides a unique opportunity to access basic QCD dynamics, the exact production mechanisms are not yet fully understood. Many different models can adequately describe the cross-section and transverse momentum ($p_T$) distribution of charmonium produced in proton-proton collisions, but predict different polarization. Thus, charmonium polarization measurement can provide a stringent test for various theoretical models of charmonium production.
The PHENIX experiment at RHIC has measured polarization of $J/\psi$ mesons produced in $p+p$ collisions at $\sqrt{s}=510$GeV at forward rapidity ($1.2<y<2.2$). The measurement was performed in several reference frames (Helicity, Collins-Soper, and Gottfried-Jackson), and includes the results for polar, azimuthal and frame-independent polarization coefficients as a function of transverse momentum. The results will be compared to the theoretical predictions provided by non-relativistic QCD models and to results from other experiments.
| Preferred Track | Quarkonia |
|---|---|
| Collaboration | PHENIX |
