O. Press Authors, “Proof of factorization of χcJdocumentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$chi _{ ext{cJ}}$$end{document} production in non-equilibrium QCD at RHIC and LHC in color singlet mechanism”, J Theor Appl phys, vol. 11, no. 4, Nov. 2023, doi: 10.1007/s40094-017-0267-7.