New predictions on meson decays from string splitting

16 pages, 2 figuresInternational audienceWe study certain exclusive decays of high spin mesons into mesons in models of large N_c quenched QCD at strong coupling using string theory. The rate of the process is calculated by studying the splitting of a macroscopic string on the relevant dual gravity backgrounds. In the leading channel for the decay of heavy quarkonium into two open-heavy quark states, one of the two produced mesons has much larger spin than the other. In this channel the decay rate is practically independent on the spin and has a mild dependence on the mass of the heavy quarks. Moreover, it is only power-like suppressed with the mass of the produced quark-anti quark pair. We also reconsider decays of high spin mesons made up of light quarks, confirming the linear dependence of the rate on the mass of the decaying meson. As a bonus of our computation, we provide a formula for the splitting rate of a macroscopic string lying on a Dp-brane in flat space