Study of Λ_c⁺→ Λμ⁺ν_μ and Test of Lepton Flavor Universality with Λ_c⁺→ Λℓ⁺ν_ℓ Decays

2023/06/05 by BESIII Collaboration, M. N. Achasov, Ablikim, M. +708
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions

paper · pdf · doi:10.48550/arxiv.2306.02624

openalex publication_date 2023/06/05 · openalex created_date 2023/06/07 · openalex updated_date 2026/08/03

Abstract

The measurement of the Cabibbo-favored semileptonic decay Λ_c⁺→ Λμ⁺ν_μ is reported using 4.5~fb^-1 of e⁺e^- annihilation data collected at center-of-mass energies ranging from 4.600~GeV to 4.699~GeV. The branching fraction of the decay is measured to be B(Λ_c⁺→ Λμ⁺ν_μ)=(3.48±0.14_{\rm stat.}±0.10_{\rm syst.})%, three times more precise than the prior world average result. Tests of lepton flavor universality using Λ_c⁺→ Λℓ⁺ν_ℓ (ℓ=e, μ) decays are reported for the first time, based on measurements of the differential decay rates and the forward-backward asymmetries in separate four-momentum transfer regions. The results are compatible with Standard Model predictions. Furthermore, we improve the determination of the form-factor parameters in Λ_c⁺→ Λℓ⁺ν_ℓ decays, which provide stringent tests and calibration for lattice quantum chromodynamics (LQCD) calculations.

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