# Predictions for b -> ssdbar, ddsbar decays in the SM and with new physics - High Energy Physics - Phenomenology

Abstract: The b -> ssdbar and b -> ddsbar decays are highly suppressed in the SM, andare thus good probes of new physics NP effects. We discuss in detail thestructure of the relevant SM effective Hamiltonian pointing out the presence ofnonlocal contributions which can be about \lambda^{-4} m c^2-m t^2 ~ 30% ofthe local operators \lambda = 0.21 is the Cabibbo angle. The matrix elementsof the local operators are computed with little hadronic uncertainty byrelating them through flavor SU3 to the observed \Delta S = 0 decays. Weidentify a general NP mechanism which can lead to the branching fractions ofthe b\to ss\bar d modes at or just below the present experimental bounds, whilesatisfying the bounds from K-Kbar and B {s}-Bbar {s} mixing. It involvesthe exchange of a NP field carrying a conserved charge, broken only by itsflavor couplings. The size of branching fractions within MFV, NMFV and generalflavor violating NP are also predicted. We show that in the future energyscales higher than 10^3 TeV could be probed without hadronic uncertainties evenfor b-> s and b-> d transitions, if enough statistics becomes available.

Author: Dan Pirjol, Jure Zupan

Source: https://arxiv.org/