2004/02/27 by The DELPHI Collaboration, P. Abreu, J. Abdallah +98 · 2 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1016/j.physletb.2004.01.086
published as Phys.Lett.B585:63-84,2004 · 24 pages, 7 figures
openalex publication_date 2004/02/27 · arxiv created 2004/03/27 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
The form factor of Lambdab0 baryons is estimated using 3.46 106 hadronic Z decays collected by the DELPHI experiment between 1992 and 1995. Charmed Lambdac+ baryons fully reconstructed in the pK-pi+, pK0S, and Lambda pi+pi+pi- modes, are associated to a lepton with opposite charge in order to select Lambdab0 -> Lambdac+ l- anti-nul decays. From a combined likelihood and event rate fit to the distribution of the Isgur-Wise variable w, and using the Heavy Quark Effective Theory (HQET), the slope of the b-baryon form factor is measured to be: rho-hat2 = 2.03 +/- 0.46 (stat) +0.72-1.00 (syst). The exclusive semileptonic branching fraction Br(Lambdab0 -> Lambdac+ l- anti-nul) can be derived from rho-hat2 and is found to be (5.0+1.1-0.8 (stat) +1.6-1.2 (syst))%. Limits on other branching fractions are also obtained.