Measurements of branching fractions of Λc+→Σ+η and Λc+→Σ+η′ and asymmetry parameters of Λc+→Σ+π0 , Λc+→Σ+η , and Λc+→Σ+η′

Abstract

We report a study of Λc+→Σ+π0, Λc+→Σ+η, and Λc+→Σ+η′ using the data sample corresponding to an integrated luminosity of 980 fb−1 collected with the Belle detector at the KEKB asymmetric-energy e+e− collider. The branching fractions relative to Λc+→Σ+π0 are measured as BΛc+→Σ+η/BΛc+→Σ+π0=0.25±0.03±0.01 and BΛc+→Σ+η′/BΛc+→Σ+π0=0.33±0.06±0.02. Using BΛc+→Σ+π0=(1.25±0.10)%, we obtain BΛc+→Σ+η=(3.14±0.35±0.17±0.25)×10−3 and BΛc+→Σ+η′=(4.16±0.75±0.25±0.33)×10−3. Here the uncertainties are statistical, systematic, and from BΛc+→Σ+π0, respectively. The ratio of the branching fraction of Λc+→Σ+η′ with respect to that of Λc+→Σ+η is measured to be BΛc+→Σ+η′/BΛc+→Σ+η=1.34±0.28±0.08. We update the asymmetry parameter of Λc+→Σ+π0, αΣ+π0=−0.48±0.02±0.02, with a considerably improved precision. The asymmetry parameters of Λc+→Σ+η and Λc+→Σ+η′ are measured to be αΣ+η=−0.99±0.03±0.05 and αΣ+η′=−0.46±0.06±0.03 for the first time.1 MoreReceived 23 August 2022Accepted 8 December 2022DOI:https://doi.org/10.1103/PhysRevD.107.032003Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBranching fractionPhysical SystemsCharmed baryonsTechniquesLepton collidersParticles & Fields