ar X iv : h ep - p h / 97 10 54 0 v 1 3 0 O ct 1 99 7 Instantons , Spin Crisis and High Q 2 Anomaly at HERA

The contribution of the nonperturbative quark-gluon interaction induced by the instantons to g p 1 (x, Q 2) and F p 2 (x, Q 2) structure functions is estimated. It is shown, that nontrivial Q 2 dependence of the instanton contribution to g p 1 (x, Q 2) allows us to explain the observed violation of the Ellis-Jaffe sum rule without involving a large positive gluon polarization. It is demonstrated that the anomalous enhancement of the instanton contribution to F p 2 (x, Q 2) structure function due to multiply emission of the gluons from instanton vertex can be one of the reason for the high Q 2 , x excess of the DIS events at HERA.