J/$\psi$ and $\psi(2S)$ measurement in $p$+$p$ collisions at $\sqrt{s} =$ 200 and 500 GeV in the STAR experiment

TL;DR

This paper reports measurements of J/ψ and ψ(2S) production and polarization in proton-proton collisions at 200 and 500 GeV, providing new insights into quarkonium production mechanisms.

Contribution

It presents the first measurement of the ψ(2S) to J/ψ ratio at 500 GeV and detailed polarization results at these energies.

Findings

J/ψ cross section and polarization measured at both energies.

First ψ(2S) to J/ψ ratio measurement at 500 GeV.

Results contribute to understanding quarkonium production.

Abstract

In this paper, results on the J/$\psi$ cross section and polarization measured via the dielectron decay channel at mid-rapidity in $p+p$ collisions at $\sqrt{s}$ = 200 and 500 GeV in the STAR experiment are discussed. The first measurement of $\psi(2S)$ to J/$\psi$ ratio at $\sqrt{s}$ = 500 GeV is also reported.