Failure of the collinear expansion in calculation of the induced gluon emission

Aurenche, P.; Zakharov, B. G.; Zaraket, H.

Failure of the collinear expansion in calculation of the induced gluon emission

Authors

Aurenche, P.

Zakharov, B. G.

Zaraket, H.

Description

We demonstrate that the collinear expansion fails in the case of gluon emission from a fast quark produced in $eA$ DIS. In this approximation the N=1 rescattering contribution to the gluon spectrum vanishes. We show that the higher-twist approach by Guo, Wang and Zhang [4,5] based on the collinear expansion is wrong. The nonzero gluon spectrum obtained in [4,5] is a consequence of unjustified neglecting some important terms in the collinear expansion.
10 pages, 2 eps figures