Ablikim, M.Achasov, M. N.Adlarson, P.Albrecht, M.Aliberti, R.Amoroso, A.Çetin, Serkant Ali2024-05-192024-05-1920222470-00102470-0029https://doi.org10.1103/PhysRevD.106.112010https://hdl.handle.net/20.500.12713/5791Using 4.5 fb(-1) of e(+)e(-) annihilation data samples collected at the center-of-mass energies ranging from 4.600 GeV to 4.699 GeV with the BESIII detector at the BEPCII collider, a first study of the semileptonic decays Lambda(+)(c) -> pK(-)e(+)v(e), Lambda(+)(c) ->Lambda (1520)e(+)v(e) and Lambda(+)(c) -> Lambda (1405)e(+)v(e) is performed. The Lambda(+)(c) -> pK(-)e(+)v(e) decay is observed with a significance of 8.2 sigma and the branching fraction is measured to be B (Lambda(+)(c) -> pK(-)e(+)v(e)) = (0.88 +/- 0.17(stat) +/- 0.07(syst)) x 10(-3). We also report evidence of Lambda(+)(c) ->Lambda (1520)e(+)v(e) and Lambda(+)(c) -> Lambda (1405)e(+)v(e) with significances of 3.3 sigma and 3.2 sigma , respectively, and measure B (Lambda(+)(c) ->Lambda (1520)e(+)v(e) ) = (1.02 +/- 0.52(stat) +/- 0.11(syst) ) x 10(-3) andB (Lambda(+)(c) ->Lambda (1405) [-> pK(-)]e(+)v(e)) = (0.42 +/- 0.19(stat) +/- 0.04(syst)) x 10(-3). Combining these with the inclusive semileptonic Lambda(+)(c) branching fraction measured by BESIII, the relative fraction is determined to be [B (Lambda(+)(c) -> pK(-)e(+)v(e))/[B (Lambda(+)(c) -> Xe(+)v(e))] = (2.1 +/- 0.4(stat) +/- 0.2(syst))%, which provides a clear confirmation that semileptonic Lambda(+)(c) decays are not saturated by the Lambda l(+)v(e) final state.eninfo:eu-repo/semantics/openAccessLatticeArticle10611WOS:000928290800002Q110.1103/PhysRevD.106.112010