Decays of near BPS heterotic strings
  The decay of highly excited massive string states in compactified heterotic string theories is discussed. We calculate the decay rate and spectrum of states carrying momentum and winding in the compactified direction. The longest lived states in the spectrum are near BPS states whose decay is dominated by a single decay channel of massless radiation which brings the state closer to being BPS. 
Michael Gutperle and Darya Krym