Study of the Hadronic Decays of \chi_c States

TL;DR

This study measures various hadronic decay branching fractions of _c states using (2S) decays, providing first-time measurements and improved precision, and also determines the masses of _c0 and .

Contribution

It provides the first measurements of several hadronic decay modes of _c states and improves the precision of known decay branching fractions and masses.

Findings

Branching fractions for multiple _c decay modes measured for the first time.

Masses of _c0 and  determined with improved accuracy.

Abstract

Hadronic decays of the P-wave spin-triplet charmonium states \chi_cJ (J=0,1,2) are studied using a sample of \psi(2S) decays collected by the BES detector operating at the BEPC storage ring. Branching fractions for the decays \chi_c1 going to K_s^0 K^+ \pi^- + c.c., \chi_c0 going to K_s^0 K_s^0, \chi_c2 going to K_s^0 K_s^0, \chi_c0 going to \phi \phi, \chi_c2 going to \phi \phi and \chi_cJ going to K^+ K^- K^+ K^- are measured for the first time, and those for \chi_cJ going to \pi^+ \pi^- \pi^+ \pi^-, $ \chi_cJ going to \pi^+ \pi^- K^+ K^-, \chi_cJ going to \pi^+ \pi^- p \bar{p} and \chi_cJ going to 3(\pi^+ \pi^-) are measured with improved precision. In addition, we determine the masses of the \chi_c0 and \eta_c to be M_{\chi_{c0}}=3414.1 \pm 0.6(stat) \pm 0.8 (sys) MeV and M_{\eta_c}=2975.8 \pm 3.9(stat) \pm 1.2 (sys) MeV.