Soft Jets and Top Mass Measurement at the Tevatron
  Extra soft jets in top events in $p \bar p$ collisions may arise not only from gluons radiated off initial state partons or final state $b$ quarks, but may also be radiated from the $t$ quarks themselves. We discuss predictions for distributions of soft gluons in $t \bar t$ production at the Tevatron and the implications for attempts to measure the top mass by reconstructing the invariant mass of its decay products. 
Lynne H. Orr and W.J. Stirling