Proton decay in 5D SU(6) GUT with orbifold S^1/Z_2 breaking in   Scherk-Schwarz mechanism
  Proton decay within 5-dimensional SU(6) GUT with orbifold S^1/Z_2 breaking is investigated using Scherk-Schwarz mechanism. It is shown that in the model neither leptoquark like heavy gauge bosons nor violation of baryon number conservation are allowed due to the orbifold breaking parity splitting. These results prevent too short proton lifetime within the model. 
A. Hartanto, F.P. Zen, J. S. Kosasih, L.T. Handoko
hep-ph