Associated production of prompt photons and heavy quarks in off-shell gluon–gluon fusion S.P. Baranov, A.V. Lipatov and N.P. Zotov Eur. Phys. J. C, 56 3 (2008) 371-378 Published online: 17 July 2008 DOI: 10.1140/epjc/s10052-008-0654-y