Observation of \chi_{cJ} decaying into the p\bar{p}K^{+}K^{-} final state

TL;DR

This paper reports the first measurements of $oldsymbol{ ext{chi}_{cJ}}$ decays into $oldsymbol{par{p}K^{+}K^{-}}$ final states, revealing intermediate resonance states and branching fractions, thus providing new insights into the properties of $oldsymbol{ ext{chi}_{cJ}}$ states.

Contribution

It presents the first observation of $ ext{chi}_{cJ}$ decays to unstable baryon resonances and measures their branching fractions using a large data sample from BESIII.

Findings

Observation of intermediate $oldsymbol{ ext{phi} o K^{+}K^{-}}$ and $oldsymbol{ ext{Lambda}(1520) o pK^{-}}$ resonances.

First measurements of branching fractions for $oldsymbol{ ext{chi}_{cJ} o ar{p}K^{+} ext{Lambda}(1520)}$, $oldsymbol{ ext{Lambda}(1520)ar{ ext{Lambda}}(1520)}$, and $oldsymbol{ ext{phi} p ar{p}}$.

Measurement of branching fractions for direct $oldsymbol{ ext{chi}_{cJ} o par{p}K^{+}K^{-}}$ decays.

Abstract

First measurements of the decays of the three $\chi_{cJ}$ states to $p\bar{p}K^{+}K^{-}$ final states are presented. Intermediate $\phi\to K^{+}K^{-}$ and $\Lambda(1520)\to pK^{-}$ resonance states are observed, and branching fractions for $\chi_{cJ}\to \bar{p}K^{+}\Lambda(1520)$, $\Lambda(1520) \bar{\Lambda}(1520)$, and $\phi p\bar{p}$ are reported. We also measure branching fractions for direct $\chi_{cJ}\to p\bar{p} K^{+}K^{-}$ decays. These are first observations of $\chi_{cJ}$ decays to unstable baryon resonances and provide useful information about the $\chi_{cJ}$ states. The experiment uses samples of $\chi_{cJ}$ mesons produced via radiative transitions from 106 million $\psi^{\prime}$ mesons collected in the BESIII detector at the BEPCII $e^+e^-$ collider.