Observation and branching fraction measurements of $\chi_{cJ}\to p \bar p K^0_S K^0_S$

TL;DR

This paper reports the first observation of the decay modes of $ ext{chi}_{cJ}$ particles into $p ar{p} K^0_S K^0_S$, measuring their branching fractions with high statistical significance using a large dataset from BESIII.

Contribution

The study provides the first measurements of branching fractions for $ ext{chi}_{cJ} o p ar{p} K^0_S K^0_S$ decays, expanding understanding of charmonium decay channels.

Findings

First observation of these decay modes with >5σ significance.

Measured branching fractions for $ ext{chi}_{c0}$, $ ext{chi}_{c1}$, and $ ext{chi}_{c2}$ decays.

No significant structures found in the analyzed mass spectra.

Abstract

Based on $(2.712\pm0.014)\times10^9$ $\psi(3686)$ events collected with the BESIII detector, the decays $\chi_{cJ} \to p \bar{p} K^{0}_{S} K^{0}_{S}$ ($J=0,1,2$) are observed for the first time with statistical significances exceeding $5\sigma$.The measured branching fractions are $\mathcal{B}(\chi_{c0}\to p \bar p K^{0}_{S} K^{0}_{S})=(6.94\pm0.30\pm0.38)\times10^{-5}$, $\mathcal{B}(\chi_{c1}\to p \bar p K^{0}_{S} K^{0}_{S})=(1.30\pm0.12\pm0.08)\times10^{-5}$, and $\mathcal{B}(\chi_{c2}\to p \bar p K^{0}_{S} K^{0}_{S})=(2.54\pm0.17\pm0.15)\times10^{-5}$, where the first uncertainties are statistical and the second systematic. In addition, no significant structures are observed in the $p\bar p$, $p K^0_S$, and $\bar p K^0_S$ mass spectra.