Study of the processes χcJ → Ξ−$$ \overline{\Xi} $$ + and Ξ0 $$ \overline{\Xi} $$0

Abstract

Using 448.1 × 106ψ(3686) decays collected with the BESIII detector at the BEPCII e+e− storage rings, the branching fractions and angular distributions of the decays χcJ→ Ξ−$$ \overline{\Xi} $$ Ξ ¯ + and Ξ0$$ \overline{\Xi} $$ Ξ ¯ 0 (J = 0, 1, 2) are measured based on a partial-reconstruction technique. The decays χc1→ Ξ0$$ \overline{\Xi} $$ Ξ ¯ 0 and χc2→ Ξ0$$ \overline{\Xi} $$ Ξ ¯ 0 are observed for the first time with statistical significances of 7σ and 15σ, respectively. The results of this analysis are in good agreement with previous measurements and have significantly improved precision.

First Simultaneous Measurement of $Ξ^0$ and $\barΞ^0$ Asymmetry Parameters in $ψ(3686)$ Decay

“…The correction to the Ξ 0 reconstruction efficiency differences is evaluated as in Refs. [38][39][40][41][42][43][44][45][46], and the same procedure is applied to estimate the systematic uncertainty. The 6C kinematic fit is sensitive to differences in the momentum resolution of the charged tracks between data and simulations.…”