Measurement of the absolute branching fraction of the inclusive decay <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mover accent="true"><mml:mi mathvariant="normal">Λ</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover><mml:mi>c</mml:mi><mml:mo>−</mml:mo></mml:msubsup><mml:mo stretchy="false">→</mml:mo><mml:mover accent="true"><mml:mi>n</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover><mml:mo>+</mml:mo><mml:mi>X</mml:mi></mml:math>

Based on e+e− collision data corresponding to an integrated luminosity of 4.5 fb−1 collected at the center-of-mass energies between 4.600 and 4.699 GeV with BESIII detector BEPCII, absolute branching fraction inclusive decay Λ¯c−→n¯+X, where X refers any possible final state particles, is measured. The determined be B(Λ¯c−→n¯+X)=(32.4±0.7±1.5)%, first uncertainty statistical second systematic. Assuming CP symmetry, measurement indicates that about one fourth Λc+ (Λ¯c−) modes a neutron (an antineutron) in have not been observed.Received 19 October 2022Accepted July 2023DOI:https://doi.org/10.1103/PhysRevD.108.L031101Published by American Physical Society under terms Creative Commons Attribution 4.0 International license. Further distribution this work must maintain attribution author(s) published article’s title, journal citation, DOI. Funded SCOAP3.Published SocietyPhysics Subject Headings (PhySH)Research AreasBranching fractionHadronic decaysPhysical SystemsCharmed baryonsParticles & Fields