Measurements of the Branching Fractions of the Semileptonic Decays <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msubsup><mml:mrow><mml:mi mathvariant="normal">Ξ</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msubsup><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mrow><mml:mi mathvariant="normal">Ξ</mml:mi></mml:mrow><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mrow><mml:mo>…

Using data samples of 89.5 and 711 fb−1 recorded at energies s=10.52 10.58 GeV, respectively, with the Belle detector KEKB e+e− collider, we report measurements branching fractions semileptonic decays Ξc0→Ξ−ℓ+νℓ (ℓ=e or μ) CP-asymmetry parameter Ξc0→Ξ−π+ decay. The are measured to be B(Ξc0→Ξ−e+νe)=(1.31±0.04±0.07±0.38)% B(Ξc0→Ξ−μ+νμ)=(1.27±0.06±0.10±0.37)%, decay αΞπ is 0.63±0.03±0.01 much improved precision compared current world average. corresponding ratio B(Ξc0→Ξ−e+νe)/B(Ξc0→Ξ−μ+νμ) 1.03±0.05±0.07, which consistent expectation lepton flavor universality. first asymmetry ACP=(αΞ−π++αΞ¯+π−)/(αΞ−π+−αΞ¯+π−)=0.024±0.052±0.014 found zero. second uncertainties above statistical systematic, while third ones arise due uncertainty fraction.Received 15 March 2021Revised 6 July 2021Accepted 18 August 2021DOI:https://doi.org/10.1103/PhysRevLett.127.121803Published 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 AreasLeptonic, & radiative decaysPhysical SystemsCharmed baryonsLepton collidersPropertiesCP violationParticles Fields