Astrophysical limits on gravitino mass

Abstract

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 m_3/2. The range of eliminated values of m_3/2 stretches over six orders of magnitude and is given by 2×10⁸<m_g̅/m_3/2<6×10¹³ m_g̅ being the gluino mass. Combining our result with the earlier analysis from colliders (m_g̅/m_3/2<2.7×10¹⁴) we conclude that (m_g̅/m_3/2<0 (10⁸) except for a narrow window around 10¹⁴. Together with the current experimental limit on m_g̅ and cosmological constraints on m_3/2, albeit model dependent, our analysis shows that a light gravitino is on the verge of being ruled out.