J/Ψproduction

摘要

For more than 25 yearsJΨ production has helped to sharpen our understanding of QCD. In proton induced reaction some observations are rather well understood while others are still unclear. The current status of the theory ofJΨ production will be sketched, paying special attention to the issues of formation time andJΨ re-interaction in a nuclear medium. Keywords Heavy quarkonium - nuclear suppression PACS Nos 13.75.-n - 12.38.Bx - 13.85.Lg - 14.40.Gx