Radiative $p_{\perp }$-broadening of fast partons in an expanding quark-gluon plasma

We study contribution of radiative processes to $p_{\perp }$-broadening of fast partons in an expanding quark-gluon plasma. It is shown that the radiative correction to $⟨p_{\perp }^2⟩$ for the QGP produced in $AA$-collisions at RHIC and LHC may be negative, and comparable in absolute value with the non-radiative contribution. We have found that the QGP expansion enhances the radiative suppression of $p_{\perp }$-broadening as compared to the static medium.