Non-factorizable Contributions to the Large Rapidity Gap at HERA

The large rapidity gap events from HERA are analyzed within a model containing a pomeron and an $f$-reggeon contribution. The choice for the pomeron contribution is based on the Donnachie-Landshoff model. The dependence of the “effective intercept” of the pomeron on the momentum fraction $\beta$ and on its Bjorken variable $\xi$ is calculated.