Measurement of the Λb0 decay form factor
Abstract
The form factor of Λb0 baryons is estimated using 3.46×106 hadronic Z decays collected by the DELPHI experiment between 1992 and 1995. Charmed Λc+ baryons fully reconstructed in the pK-π+, pK0S, and Λπ+π+π- modes, are associated to a lepton with opposite charge in order to select Λb0→Λc+l-ν¯l 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 ρ̂2=2.03±0.46(stat)+0.72-1.00(syst). The exclusive semileptonic branching fraction Br(Λb0→Λc+l-ν¯l) can be derived from ρ̂2 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.
- Publication:
-
Physics Letters B
- Pub Date:
- April 2004
- DOI:
- 10.1016/j.physletb.2004.01.086
- arXiv:
- arXiv:hep-ex/0403040
- Bibcode:
- 2004PhLB..585...63A
- Keywords:
-
- High Energy Physics - Experiment
- E-Print:
- 24 pages, 7 figures