Color octet contribution to J/ψ production at a photon linear collider

We investigate J/ψ production at a Photon Linear Collider (PLC) in the framework of NRQCD factorization approach. It was shown that color octet contribution is dominating in charmonium production at PLC. The main fraction of J/ψ comes from the single and double resolved photon processes. Expected cross sections of charmonium states production are large enough even at pT>5 GeV to expect several hundreds of J/ψʹs through the leptonic decays channel for a projected integral PLC luminosity of 50 fb−1.