Radiative corrections to semi-inclusive deep inelastic scattering induced by lepton and photon pair electroproduction

The contribution of lepton and photon pair production in ep-scattering to the cross section of semi-inclusive deep inelastic scattering ep-> e’p’X has been calculated. The numerical results showed a large contribution of this processes at ${\varphi }_h={180}^o$, in a good agreement with preliminary experimental data.