Ioffe-time distribution of quarks in the photon

We have analysed the Ioffe-time distribution of quarks in virtual photons using Operator Product Expansion of the correlation function that determines the matrix element of the corresponding quark string operator. The distribution for a transversally polarised photon admits a spectral representation which can be continued to the on-shell region p = 0. The resulting model Ioffe-time distribution turns out to be larger than parametrisations of the available F γ 2 data. This result is linked to the slope of the quark distribution at the origin, which is also too large. ∗on leave of N. Copernicus Astronomical Center, Bartycka 18, PL–00–716 Warsaw, Poland