Factorization in deep inelastic scattering at Bj\"{o}rken limit: Reduction to (1+1)D integrable models

We investigate structure functions in deep inelastic scattering processes (DIS) at Bj"{o}rken limit and found that they are factorized into the longitudinal and transversal parts. We see that the longitudinal part can be linked to exact form factors calculated earlier in 1+1 dimensional integrable quantum field theories, such as sine-Gordon model. We extract asymptotic of Form-factors at small Bj"{o}rken parameter $x$ and compare it with experimental data of HERA and ZEUS collaborations on Deep inelastic lepton-proton scattering. We observe the factorization of the structure functions $F_2(x,q^2)$ and find out its power behavior on scaling parameter $x$.