Measurements of branching fractions and asymmetry parameters of $\Xi^0_c\to \Lambda\bar K^{*0}$, $\Xi^0_c\to \Sigma^0\bar K^{*0}$, and $\Xi^0_c\to \Sigma^+K^{*-}$ decays at Belle.

Abstract

Using a data sample of 980 fb−1 collected with the Belle detector at the KEKB asymmetric-energy e +e − collider, we study the processes of Ξ 0 c → ΛK¯ ∗0 , Ξ 0 c → Σ 0K¯ ∗0 , and Ξ 0 c → Σ +K∗− for the first time. The relative branching ratios to the normalization mode of Ξ 0 c → Ξ −π + are measured to be B(Ξ0 c → ΛK¯ ∗0 )/B(Ξ0 c → Ξ −π +) = 0.18 ± 0.02(stat.) ± 0.01(syst.), B(Ξ0 c → Σ 0K¯ ∗0 )/B(Ξ0 c → Ξ −π +) = 0.69 ± 0.03(stat.) ± 0.03(syst.), B(Ξ0 c → Σ +K∗−)/B(Ξ0 c → Ξ −π +) = 0.34 ± 0.06(stat.) ± 0.02(syst.), where the uncertainties are statistical and systematic, respectively. We obtain B(Ξ0 c → ΛK¯ ∗0 ) = (3.3 ± 0.3(stat.) ± 0.2(syst.) ± 1.0(ref.)) × 10−3 , B(Ξ0 c → Σ 0K¯ ∗0 ) = (12.4 ± 0.5(stat.) ± 0.5(syst.) ± 3.6(ref.)) × 10−3 , B(Ξ0 c → Σ +K∗−) = (6.1 ± 1.0(stat.) ± 0.4(syst.) ± 1.8(ref.)) × 10−3 , where the uncertainties are statistical, systematic, and from B(Ξ0 c → Ξ −π +), respectively. The asymmetry parameters α(Ξ0 c → ΛK¯ ∗0 ) and α(Ξ0 c → Σ +K∗−) are 0.15 ± 0.22(stat.) ± 0.04(syst.) and −0.52 ± 0.30(stat.) ± 0.02(syst.), respectively, where the uncertainties are statistical followed by systematic.