Power Corrections to Fragmentation Functions in Non-Singlet Deep   Inelastic Scattering
  We investigate the power-suppressed corrections to the fragmentation functions of the current jet in non-singlet deep inelastic lepton-hadron scattering. The current jet is defined by selecting final-state particles in the current hemisphere in the Breit frame of reference. Our method is based on an analysis of one-loop Feynman graphs containing a massive gluon, which is equivalent to the evaluation of leading infrared renormalon contributions. We find that the leading corrections are proportional to $1/Q^2$, as in $e^+e^-$ annihilation, but their functional forms are different. We give quantitative estimates based on the hypothesis of universal low-energy behaviour of the strong coupling. 
M. Dasgupta, G.E. Smye and B.R. Webber