New predictions on meson decays from string splitting

TL;DR

This paper models high spin meson decays using string theory in large N_c Yang-Mills, calculating decay rates via string splitting in gravity backgrounds, revealing power-like suppression and linear dependencies.

Contribution

It introduces a string-theoretic approach to predict meson decay rates, including a new formula for string splitting on Dp-branes in flat space.

Findings

Decay rate for heavy quarkonium decay is power-like suppressed with quark mass.

Decay rate for light quark mesons depends linearly on meson mass.

Derived a general formula for string splitting on Dp-branes.

Abstract

We study certain exclusive decays of high spin mesons into mesons in models of large N_c Yang-Mills with few flavors 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 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.