Electroweak Penguin and Leptophobic $Z^\prime$ model
  We consider the leptophobic $Z^\prime$ model which can appear naturally in the flipped SU(5) or string-inspired $E_6$ models. This model can be constrained by measurements of the $B\to M \nu\bar{\nu}$ decays and $\Delta m_s$. We find that although the latter give much stronger constraints on the coupling than the former, they are complementary to each other. 
S. Baek, J. H. Jeon, C. S. Kim (Yonsei U.), and Chaehyun Yu (korea U.)