Measurements of the branching fractions of $$ {\Xi}_c^0\to {\Xi}^0{\pi}^0 $$, $$ {\Xi}_c^0\to {\Xi}^0\eta $$, and $$ {\Xi}_c^0\to {\Xi}^0{\eta}^{\prime } $$ and asymmetry parameter of $$ {\Xi}_c^0\to {\Xi}^0{\pi}^0 $$

We present a study of Ξ0c → Ξ0 π 0 , Ξ0c → Ξ0 η, and Ξ0c → Ξ0 η ′ decays using the Belle and Belle II data samples, which have integrated luminosities of 980 fb−1 and 426 fb−1 , respectively. We measure the following relative branching fractions B(Ξ0c → Ξ0 π 0 )/B(Ξ0c → Ξ− π + ) = 0.48 ± 0.02(stat) ± 0.03(syst), B(Ξ0c → Ξ0 η)/B(Ξ0c → Ξ− π + ) = 0.11 ± 0.01(stat) ± 0.01(syst), B(Ξ0c → Ξ0 η ′ )/B(Ξ0c → Ξ− π + ) = 0.08 ± 0.02(stat) ± 0.01(syst) for the first time, where the uncertainties are statistical (stat) and systematic (syst). By multiplying by the branching fraction of the normalization mode, B(Ξ0c → Ξ− π + ), we obtain the following absolute branching fraction results B(Ξ0c → Ξ0 π 0 ) = (6.9 ± 0.3(stat) ± 0.5(syst) ± 1.3(norm)) × 10−3 , B(Ξ0c → Ξ0 η) = (1.6 ± 0.2(stat) ± 0.2(syst) ± 0.3(norm)) × 10−3 , B(Ξ0c → Ξ0 η ′ ) = (1.2 ± 0.3(stat) ± 0.1(syst) ± 0.2(norm)) × 10−3 , where the third uncertainties are from B(Ξ0c → Ξ− π + ). The asymmetry parameter for Ξ0c → Ξ0 π 0 is measured to be α(Ξ0c → Ξ0 π 0 ) = −0.90 ± 0.15(stat) ± 0.23(syst).