Inclusive decays of $\eta_{b}$ into $S$- and $P$-wave charmonium states

TL;DR

This paper calculates inclusive S- and P-wave charmonium production in $$ decays using NRQCD, highlighting the importance of certain decay channels for understanding the color-octet mechanism and exotic states.

Contribution

It provides the first leading-order NRQCD calculation of inclusive charmonium production in $$ decays, emphasizing the significance of specific decay pathways.

Findings

The decay channel $ o _J + g g$ significantly contributes to $J/$ production.

The study offers insights into the color-octet mechanism in $$ decays.

Results may shed light on the nature of X(3940) and X(3872).

Abstract

Inclusive S- and P-wave charmonium productions in the bottomonium ground state $\eta_b$ decay are calculated at the leading order in the strong coupling constant $\alpha_s$ and quarkonium internal relative velocity $v$ in the framework of the NRQCD factorization approach. We find the contribution of $\eta_b \to \chi_{c_J}+ g g$ followed by $\chi_{c_J} \to J/\psi+ \gamma$ is also very important to the inclusive $J/\psi$ production in the $\eta_b$ decays, which maybe helpful to the investigation of the color-octet mechanism in the inclusive $J/\psi$ production in the $\eta_b$ decays in the forthcoming LHCb and SuperB. As a complementary work, we also study the inclusive production of $\eta_c$, and $\chi_{cJ}$ in the $\eta_b$ decays, which may help us understand the X(3940) and X(3872) states.