Double charmonium production in exclusive bottomonia decays

TL;DR

This paper investigates exclusive bottomonia decays producing double charmonium states, revealing violations of traditional selection rules through calculations in light cone formalism and nonrelativistic QCD.

Contribution

It demonstrates that certain P-wave charmonia with non-zero angular momentum can be produced at leading twist, challenging existing suppression predictions.

Findings

Production of some P-wave charmonia with Lz ≠ 0 is allowed at leading twist.

Selection rules predicting suppression are violated.

Decay widths are calculated using light cone and nonrelativistic QCD models.

Abstract

This paper is devoted to the leading twist exclusive bottomonia decays with double charmonium in the final state. Using models of the twist-2 charmonia distribution amplitudes the widths of these decays are calculated within light cone formalism. In addition, the processes under consideration are studied within nonrelativistic QCD. In our analysis we have found that the production of some of the $P$-wave charmonia mesons with $L_z \neq 0$ is allowed already at the leading twist approximation. This means that the selection rules which predict the suppression of such decays are violated. The mechanism which lies behind this violation is discussed.