Search for excited leptons in e+ e- collisions at s**(1/2) = 161-GeV

Collaboration
Oct, 1996
18 pages
Published in:
  • Phys.Lett.B 391 (1997) 197-209
Report number:
  • CERN-PPE-96-138
Experiments:

Citations per year

199720002003200620090123456
Abstract: (Elsevier)
We have searched for excited states of charged and neutral leptons, e ∗ , μ ∗ , τ ∗ and ν ∗ , in e + e − collisions at s =161 GeV using the OPAL detector at LEP. No evidence for their existence was found. With the most common coupling assumptions, the topologies from excited lepton pair production include ℓ + ℓ − γγ and ℓ + ℓ − W + W − , with the subsequent decay of the virtual W bosons. From the analysis of these topologies, 95% confidence level lower mass limits of 79.9 GeV for e ∗ , 80.0 GeV for μ ∗ , 79.1 GeV for τ ∗ , 78.3 GeV for ν e ∗ , 78.9 GeV for ν μ ∗ and 76.2 GeV for ν τ ∗ are inferred. From the analysis of W + W − and γγ topologies with missing energy and using alternative coupling assingments which favour charged ℓ ∗± and photonic ν ∗ decays, 95% confidence level lower mass limits of 77.1 GeV for each ℓ ∗± flavour and 77.8 GeV for each ν ∗ flavour are inferred. From the analysis of the ℓ + ℓ − γ , ℓ ± W ∓ and single γ final states expected from excited lepton single production, upper limits on the ratio of the coupling to the compositeness scale, f Λ , are determined for excited lepton masses up to the kinematic limit.
  • electron positron: colliding beams
  • electron positron: annihilation
  • lepton: excited state
  • excited state: decay modes
  • lepton: pair production
  • mass: excited state
  • lower limit
  • OPAL
  • experimental results
  • CERN LEP Stor