Measurement of the average lifetime of b-hadrons in Z decays

• Autores: Dova, María Teresa; L3 Collaboration
• Año de publicación: 1998
• Idioma: español castellano
• Tipo de recurso: artículo
• Materia: Ciencias Exactas; Física; b-hadron lifetime; colider LEP; Z decays
• Institución: Universidad Nacional de La Plata

We present a measurement of the average b-hadron lifetime t at the eqey collider LEP. Using hadronic Z decays b collected in the period from 1991 to 1994, two independent analyses have been performed. In the first one, the b-decay position is reconstructed as a secondary vertex of hadronic b-decay particles. The second analysis is an updated measurement of t using the impact parameter of leptons with high momentum and high transverse momentum. The combined result is $\text{τ}{}_{\mathrm{<mtext>b</mtext>}}\text{=[1549±9}\text{(stat)}\text{±15}\text{(syst)]}\text{fs}\text{.}$ In addition, we measure the average charged b-decay multiplicity 〈nb〉and the normalized average b-energy 〈xE〉b at LEP to be $\text{〈n}{}_{\mathrm{<mtext>b</mtext>}}\text{〉=4.90±0.04}\text{(stat)±0.11}\text{(syst),}\text{〈x}{}_{\mathrm{E}}\text{〉}{}_{\mathrm{<mtext>b</mtext>}}\text{=0.709±0.004}\text{(stat+syst).}$
Facultad de Ciencias Exactas