Test the flavour structure of diffractive parton densities

Determine whether the flavour-democratic assumption for the light-quark content of diffractive parton distribution functions is valid, especially for the strange-quark distribution.

Background

Diffractive parton-density fits generally use only a gluon density and a flavour-symmetric quark singlet density, treating the up, down, and strange quarks and antiquarks democratically. The paper characterizes this assumption as ad hoc rather than as a consequence of established diffractive QCD dynamics.

The diffractive charged-current cross section is identified as the only measurement available at the time with sensitivity to the light-quark flavour decomposition. More precise or additional measurements are therefore needed to test the assumed flavour structure.