The additive quark model revisited: Hadron- and photon-induced cross sections

Abstract. The standard additive quark model and the ensuing counting rules are modified to take into account not only the quark–gluonic content of the Pomeron but also of the secondary Reggeons, as well as the fact that the soft Pomeron is not just a gluonic ladder. A much-improved description of pp, $\pi p$, $\gamma p$ and $\gamma \gamma$ cross sections is obtained.