Measurement of momentum spectra of charged hadrons in dijet photoproduction with ZEUS at HERA

Scaled momentum distributions of charged hadrons in dijet photoproduction
were measured with ZEUS at HERA. They  are used to test the predictions of
the modified leading-logarithm approximation (MLLA), suplemented with
the local parton-hadron-duality (LPHD) model for hadronisation. The
photoproduction data were used to extract the energy scale 
parameter, lambda_eff, in the MLLA model. The value obtained is
compared to other values extracted from ep, ee and ppbar data in order to
test the universality of lambda_eff.