Search for excited charged leptons in Z0 decays
Zeitschrift für Physik C Particles and Fields 53:1 (1992) 41-49
Abstract:
Using a data sample of 115000 hadronic Z0 decays, a search was performed for the production of excited charged leptons decaying into an ordinary lepton and one photon. Pair production of excited leptons of mass below 45 GeV/c2 is excluded. From an analysis of the lepton-photon mass spectra this experiment is also able to exclude single production of these particles for masses that reach up to 85 GeV/c2, if the compositeness scale is below 1 TeV. © 1992 Springer-Verlag.Multiplicity dependence of mean transverse momentum in e+e- annihilations at LEP energies
Physics Letters B 276:1-2 (1992) 254-262
Abstract:
A strong increase of the mean transverse momentum 〈pt〉 with the number of charged particles nch is observed in e+e - annihilations into hadrons at LEP energies. The effect resembles correlations observed in hadron-hadron interactions. In e+e- annihilations the 〈Pt〉 and nch correlations can be accounted for by gluon radiation. © 1992.Production of strange particles in the hadronic decays of the Z0
Physics Letters B 275:1-2 (1992) 231-242
Abstract:
An analysis of the production of strange particles from the decays of the Z0 boson into multihadronic final states is presented. The analysis is based on about 90 000 selected hadronic Z0 decays collected by the DELPHI detector at LEP in 1990. Ks0, K*±, Λ(Λ) and Ξ- (Ξ+) have been identified by their characteristic decays. The measured production cross sections are compared with predictions of the Lund Monte Carlo tuned to data at PEP/PETRA energies. © 1992.Search for scalar leptoquarks from Z0 decays
Physics Letters B 275:1-2 (1992) 222-230
Abstract:
We have searched for pair produced scalar leptoquarks each decaying to a quark and a charged lepton in a sample of 116 000 hadronic Z0 events produced at LEP. No candidate was detected and cross section and branching ratio limits are set for the above process at 95% CL. Mass limits are found to be about 42 GeV/c2 depending only slightly on the models used and a coupling times branching ratio exclusion line is drawn for a scalar leptoquark with a free coupling. We have also probed the mass region above 45 GeV/c2 for a singly produced scalar leptoquark and set limits on the cross section and the coupling λ2/4π up to 60 GeV. © 1992.Study of orientation of three-jet events in Z0 hadronic decays using the DELPHI detector
Physics Letters B 274:3-4 (1992) 498-506