Central exclusive χ c meson production at the Tevatron revisited L. A. Harland-Lang, V. A. Khoze, M. G. Ryskin and W. J. Stirling Eur. Phys. J. C, 65 3-4 (2010) 433-448 Published online: 24 November 2009 DOI: 10.1140/epjc/s10052-009-1214-9