Astrophysical limits on gravitino mass

We calculate exotic cooling rates of stars due to photo-production of light particles (mostly scalars and pseudoscalars) which originate from the hidden sector of no scale supergravity theories. Using this we can restrict the gravitino mas m32. The range of eliminated values of m32 stretches over six orders of magnitude and is given by 2 × 108 < mg̃m32 < 6 × 1013, mg̃ being the gluino mass. Combining our result with the earlier analysis from colliders (mg̃m32 < 2.7 × 1014) we conclude that mg̃m32 < O(108) except for a narrow window around 1014. Together with the current experimental limit on mg̃ and cosmological constraints on m32, albeit model dependent, our analysis shows that a light gravitino is on the verge of being ruled out.