Weak decays of theHdibaryon

We calculate decay rates and branching fractions for the postulated S=-2 H dibaryon, both for the expected ΔS=1 channels (nΛ,n${\Sigma }^0$,p${\Sigma }^{\mathrm{-}}$) and for the possible ΔS=2 mode (nn). For ΔS=1 decays we find the S waves are dominated by ΔI=(3/2) transitions due to the Pauli principle, which forces the six-quark final state to be in a SU(3) 27-plet. If observed, this would be the first breakdown of the ΔI=1/2 rule. The lifetime is long, of order ${10}^{\mathrm{-}8}$ sec, which should be considered in planning experiments. In the ΔS=2 case, we add a consideration of dispersive effects to our previous calculation of the box diagram, reinforcing our conclusion that the H is too short lived to be the explanation of the Cygnus X-3 events.