### Diffraction and rapidity gap measurements in ATLAS.

Pavel Ruzicka
Pseudorapidity gap distributions in Large Hadron Collider proton-proton collisions at \sqsen\ are studied using a minimum bias data sample of integrated luminosity $7.1 \ {\rm \mu b^{-1}}$. Cross sections are measured differentially in the size \detaf of the larger of the pseudorapidity regions extending to the limits of the \mbox{ATLAS} acceptance, at $\eta = \pm 4.9$, in which no final state particles are produced above a transverse momentum threshold \ptcut. The measurements span the region...