First observation of Λ_c(2595)⁺ → Λ⁺_cπ⁰π⁰ and Λ_c(2625)⁺→ Λ⁺_cπ⁰π⁰

2025/03/27 by M. Ablikim, BESIII Collaboration, М. Н. Ачасов +750
Physics and Astronomy · #Black Holes and Theoretical Physics #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions

paper · doi:10.48550/arxiv.2503.21413

openalex publication_date 2025/03/27 · openalex created_date 2025/10/11 · openalex updated_date 2026/07/28

Abstract

By analysing e⁺e^- annihilation data corresponding to an integrated luminosity of 368.48~pb^-1 collected at the centre-of-mass energies of √(s) = 4.918 and 4.951~GeV with the BESIII detector, we report the first observation of Λ_c(2595)⁺ and Λ_c(2625)⁺→ Λ⁺_cπ⁰π⁰ with statistical significances of 7.9σ and 11.8σ, respectively. The branching fractions of Λ_c(2595)⁺ and Λ_c(2625)⁺→ Λ⁺_cπ⁰π⁰ are measured to be (59.5 ± 11.1_{\rm stat.} ± 7.9_{\rm syst.}) % and (41.0 ± 5.2_{\rm stat.} ± 3.3_{\rm syst.}) %, respectively. The absolute branching fraction of Λ_c(2595)⁺ is consistent with the expectation of the mechanism referred to as the threshold effect, proposed for the strong decays of Λ_c(2595)⁺ within uncertainty.

Related

• First measurements of the absolute branching fraction of Λ_c(2625)⁺→ Λ⁺_cπ⁺π^- and upper limit on Λ_c(2595)⁺→ Λ⁺_cπ⁺π^-
• Λ_c⁺ decays at BESIII
• Improved measurement of absolute branching fraction of the inclusive decay Λ_c⁺ → K_S⁰ X
• Measurement of the branching fractions of the decays Λ_c⁺→ΛK_S⁰K⁺, Λ_c⁺→ΛK_S⁰π⁺ and Λ_c⁺→ΛK^*+
• Measurement of the branching fractions of the Cabibbo-favored decays Λ_c⁺→ΛK_S⁰K⁺ and Λ_c⁺→Ξ⁰K_S⁰π⁺ and search for Λ_c⁺→Σ⁰ K_S⁰K⁺