PROTON DECAY WITH A LIGHT GRAVITINO OR AXINO

We consider proton decay in supersymmetric models with a, gravitino or axino lighter than the proton, This consideration leads to a stringen t limit on the R-parity and B-violating Yukawa coupling of the superpo tential operator (UjDjDkc)-D-c-D-c as lambda(112)''less than or equal to 10(-15)(m(3/2)/eV) for a light gravitino, and lambda(112)''less tha n or equal to 10(-15)(F-a/10(10) GeV) for light Dine-Fischler-Srednick i-Zhitnitskii axino. For the hadronic axino, the constraint is weakene d bg a factor of 10(3).