Measurements of branching fractions and asymmetry parameters of Ξ0c → ΛK ̄ ∗0, Ξ0c → Σ0K ̄ ∗0, and Ξ0c → Σ+K∗− decays at Belle

Journal of High Energy Physics. 2021.

Aushev T., Pakhlova G., Uglov T., Попов В. Е., Mizuk R.

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 Ξ0c→ΛK¯∗0, Ξ0c→Σ0K¯∗0, and Ξ0c→Σ+K∗− for the first time. The relative branching ratios to the normalization mode of Ξ0c→Ξ−π+ are measured to be 

{\cal
B}(\Xi^0_c\to \Lambda\bar K^{*0})/{\cal B}(\xic\to \Xi^-\pi^+)=0.18\pm0.02({\rm
stat.})\pm0.01({\rm syst.}),

{\cal B}(\Xi^0_c\to \Sigma^0\bar K^{*0})/{\cal
B}(\xic\to \Xi^-\pi^+)=0.69\pm0.03({\rm stat.})\pm0.03({\rm syst.}),

{\cal
B}(\Xi^0_c\to \Sigma^+K^{*-})/{\cal B}(\xic\to \Xi^-\pi^+)=0.34\pm0.06({\rm
stat.})\pm0.02({\rm syst.}),

where the uncertainties are statistical and systematic, respectively. We obtain %measure the branching fractions of Ξ0c→ΛK¯∗0, Ξ0c→Σ0K¯∗0, and Ξ0c→Σ+K∗− to be 

(Ξ0c→ΛK¯∗0)=(3.3±0.3(stat.)±0.2(syst.)±1.0(ref.))×10−3,

(Ξ0c→Σ0K¯∗0)=(12.4±0.5(stat.)±0.5(syst.)±3.6(ref.))×10−3,

(Ξ0c→Σ+K∗−)=(6.1±1.0(stat.)±0.4(syst.)±1.8(ref.))×10−3,

where the uncertainties are statistical, systematic, and from ${\cal B}(\xic \to \Xi^-\pi^+)$, respectively. The asymmetry parameters α(Ξ0c→ΛK¯∗0) and α(Ξ0c→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.

Keywords: high energy physics, High Energy Physics - Phenomenology

Publication based on the results of: Investigation of the nature of the bottomonium states on the data of the Belle experiment and development of new research methods in charm and tau-lepton physics in experiments on electron-positron colliders (2021)