Search for CP violation in Ξc → Σ h h− and Λc → ph h− at Belle II

Abstract

We report decay-rate CP asymmetries of the singly-Cabibbo-suppressed decays Ξþc → Σþhþh− and Λþc → phþh−, with h ¼ K, π, measured using 428 fb−1 of eþe− collisions collected by the Belle II experiment at the SuperKEKB collider. The results, ACPðΞþc → ΣþKþK−Þ ¼ ð3.7 ± 6.6 ± 0.6Þ%, ACPðΞþc → Σþπþπ−Þ ¼ ð9.5 ± 6.8 ± 0.5Þ%, ACPðΛþc → pKþK−Þ ¼ ð3.9 ± 1.7 ± 0.7Þ%, ACPðΛþc → pπþπ−Þ ¼ ð0.3 ± 1.0 ± 0.2Þ%, where the first uncertainties are statistical and the second systematic, agree with CP symmetry. From these results we derive the sums ACPðΞþc → Σþπþπ−Þþ ACPðΛþc → pKþK−Þ ¼ ð13.4 ± 7.0 ± 0.9Þ%, ACPðΞþc → ΣþKþK−Þ þ ACPðΛþc → pπþπ−Þ ¼ ð4.0± 6.6 V± 0.7Þ%, which are consistent with the U-spin symmetry pr..