We analyze the inclusive b(c)→s(u)μ+μ− and the exclusive
B(D+)→K(π+)μ+μ− flavour changing neutral current decays in
the light of HyperCP boson X0 of mass 214 MeV recently observed in the
hyperon decay Σ+→pμ+μ−. Using the branching ratio data of
the above inclusive and exclusive decays, we obtain constraints on g1​(h1​)
and g2​(h2​), the scalar and pseudo-scalar coupling constants of the
b−s−X0(c−u−X0) vertices.Comment: 18 pages, 10 eps figure