J/Psi and Psi' total cross sections and formation times from data for charmonium suppression in $pA$ collisions

TL;DR

This paper analyzes charmonium suppression in pA collisions at 800 GeV using a dynamic model of absorption cross sections, estimating formation times and total cross sections for J/Psi and Psi' states.

Contribution

It introduces a time- and energy-dependent absorption cross section model to interpret charmonium suppression data, providing estimates for formation times and total cross sections.

Findings

Pre-meson absorption cross section at au=0 is about 3 mb.

Total cross sections are approximately 2.8 mb for J/Psi and 10.5 mb for Psi' at 10 GeV.

Formation time estimated to be around 0.6 fm/c.

Abstract

The recent data for E866 experiment on the x_F dependence for charmonium suppression in pA collisions at 800 GeV are analyzed using a time- and energy-dependent preformed charmonium absorption cross section \sigma_{abs}^\psi(\tau,\sqrt{s}). For \sqrt{s}=10 GeV the initially (\tau=0) produced premeson has an absorption cross section of \sigma_{pr}~3mb. At the same energy but for \tau -> \infty one deduces for the total cross sections \sigma_{tot}^{J/Psi N}=(2.8\pm 0.3)mb, \sigma_{tot}^{J/Psi N}= (10.5\pm 3.6)mb. The date are compatible with a formation time \tau_{1/2}=0.6 fm/c.