Study of $B \to \chi_{cJ} X$ at Belle

TL;DR

This paper reports precise measurements of inclusive $B$ meson decays into $ ext{chi}_c$ states using Belle data, revealing insights into decay modes and potential new resonances.

Contribution

It provides the first precise measurements of inclusive $B o ext{chi}_c$ branching fractions and explores multi-body final states for new charmonium-like resonances.

Findings

Inclusive $B o ext{chi}_c1$ and $ ext{chi}_c2$ branching fractions measured.

Multi-body decay modes investigated for potential new resonances.

$B o ext{chi}_c2$ decays are less suppressed than two-body decay predictions.

Abstract

In spite of the fact that the two-body $B$ decays into $\chi_{c2}$ such as $B \to \chi_{c2} K^{(*)}$ are suppressed by the QCD factorization effect, the inclusive $B \to \chi_{c2} X$ branching fraction amounts to one third of the non-suppressed $B \to \chi_{c1} X$ decays because of the decay modes to the multi-body final states. Using a large statistics $\Upsilon(4S)$ data sample corresponding to 772 million $B$ meson pairs accumulated by the Belle detector at the KEKB $e^+e^-$ collider, precise measurements of inclusive $B \to \chi_{c1}$ and $\chi_{c2}$ branching fractions are carried out. The multi-body final states such as $\chi_{cJ} K \pi$, $\chi_{cJ} K \pi \pi$ and so on are also investigated to look for new charmonium-like resonance.