Central jet production as a probe of the perturbative formalism for exclusive diffraction

We propose a new variable, R-j, in order to identify exclusive double-diffractive high E-T di-jet production. The variable R-j is calculated using the transverse energy E-T and pseudorapidity of the jet with the largest ET. For a purely exclusive event the value of R-j -> 1, if we were to neglect hadronisaton and the detector resolution effects. To illustrate the expected R-j distribution we also compute exclusive three-jet production; and, moreover, we include jet smearing effects. By studying the predictions as a function of the size of the rapidity interval, delta eta, which allows for additional gluon radiation, one can probe the QCD radiation effects which are responsible for the Sudakov suppression of the exclusive amplitude. In this way we may check and improve the formalism used to predict the cross sections of exclusive double-diffractive Higgs boson (and/or other new physics) production.