D.J. Schotanus

Study of the structure of hadronic events and determination of αS at s = 130 GeV and 136 GeV

We present a study of the structure of hadronic events recorded by the L3 detector at center-of-mass energies of 130 and 136 GeV. The data sample corresponds to an integrated luminosity of 5 pb-1 collected during the high energy run of 1995. The shapes of the event shape distributions and the energy dependence of their mean values are well reproduced by QCD models. From a comparison of the data with resummed O(alpha_s^2) QCD calculations, we determine the strong coupling constant to be alpha_s(133 GeV) = 0.107 +/- 0.005(exp) +/- 0.006(theor).

The L3+C detector, a unique tool-set to study cosmic rays

AbstractThe L3 detector at the CERN electron–positron collider, LEP, has been employed for the study of cosmic ray muons.The muon spectrometer of L3 consists of a set of high-precision drift chambers installed inside a magnet with avolume of about 1000 m 3 and a field of 0:5T: Muon momenta are measured with a resolution of a few percentat 50 GeV: The detector is located under 30 m of overburden. A scintillator air shower array of 54 m by 30 mis installed on the roof of the surface hall above L3 in order to estimate the energy and the core position of theshower associated with a sample of detected muons. Thanks to the unique properties of the L3þC detector, muonresearch topics relevant to various current problems in cosmic ray and particle astrophysics can be studied. r 2002Elsevier Science B.V. All rights reserved. PACS: 95.55.Vj; 98.70.Sa; 96.40.Tv; 95.85.RyKeywords: L3+C detector; Cosmic rays; Muon spectrum; Astroparticle physics 1. IntroductionThe L3þ C experiment (Figs. 1 and 2), installedat the Large Electron Positron collider (LEP) atCERN, Geneva, consists of two major parts:firstly, below ground, the L3 muon spectrometer[1], which is comprised of a large 0:5 T magnetwith a volume of 1000 m

Search for new physics in energetic single photon production in

Using a sample of

e^{+}e^{-}

\mathrm{e^{+}e^{-}}

annihilation at the

annihilation events collected with the L3 detector at the Z resonance corresponding to an integrated luminosity of 137 pb

Z

^{-1}

resonance

, we have searched for anomalous production of

Search for neutralinos in Z decays

\gamma \mathrm{X}

Measurement of hadron and lepton-pair production at 130 GeV<root s<140 GeV at LEP

final states where

Cross-section of hadron production in

\mathrm{X}