Electroweak vector boson production at the LHC as a probe of mechanisms   of diffraction
  We show that the double diffractive electroweak vector boson production in the $pp$ collisions at the LHC is an ideal probe of QCD based mechanisms of diffraction. Assuming the resolved Pomeron model with flavor symmetric parton distributions, the $W$ production asymmetry in rapidity equals exactly zero. In other approaches, like the soft color interaction model, in which soft gluon exchanges are responsible for diffraction, the asymmetry is non-zero and equal to that in the inclusive $W$ production. In the same way, the ratio of the $W$ to $Z$ boson production is independent of rapidity in the models with resolved Pomeron in contrast to the predictions of the soft color interaction model. 
Krzysztof Golec-Biernat (INP Polish Academy of Sciences, Krakow,   University of Rzeszow), Christophe Royon (CEA Saclay), La...
hep-ph