A measurement of muon pair production in e+e- annihilation at centre of mass energies 35.0≤ {Mathematical expression}≤46.8 GeV
Zeitschrift für Physik C Particles and Fields 40:2 (1988) 163-170
Abstract:
The reaction e+e-→μ+μ- has been studied at centre of mass energies between 35.0 and 46.8 GeV using the TASSO detector at PETRA. We present measurements of the forward-backward charge asymmetry (Aμμ) and cross section σμμ for this reaction at three energies. At 35.0 GeV we obtain a cross section relative to the QED prediction of Rμμ=σμμ/σo=0.932±0.018±0.044 and Aμμ=(-10.6-2.3+2.2±0.5)%. At 38.3 GeV we find Rμμ=0.951±0.072-0.057+0.063 and Aμμ=(+1.7-8.6+8.5±0.5)%. At 43.6 GeV we measure Rμμ=0.921±0.037±0.055 and Aμμ=(-17.6-4.3+4.4±0.5)%. Our results are in good agreement with the predictions of the standard model. Including previous TASSO data we present improved determinations of muonic electroweak parameters. We also report on lower limits of possible contributions from contact interactions. © 1988 Springer-Verlag.Jet reconstruction and jet properties at HERA
Zeitschrift für Physik C Particles and Fields 39:2 (1988) 257-267
Abstract:
We discuss jet reconstruction methods with respect to their suitability for ep collisions at HERA and study the expected properties of such jets. The results are based on complete event simulation using current models of jet evolution and hadronization in combination with experimentally tested jet algorithms. The effects of calorimeter resolution are illustrated by explicit simulation of the energy profile and fluctuations in a simplified, but realistic detector. © 1988 Springer-Verlag.A measurement of the τ lifetime
Zeitschrift für Physik C Particles and Fields 39:3 (1988) 331-337
Abstract:
We have reconstructed 695 three-track τ decay vertices using a high resolution drift chamber close to the interaction point. From the distribution of decay lengths we measure the lifetime to be (3.06 ±0.20±0.14)×10−13 s. Using this result we find that the ratio of charged weak coupling constant for the τ to that of the μ, Gτ/Gμ=0.967±0.040 consistent with the concept of lepton universality. © 1988, Springer-Verlag. All rights reserved.A search for particles with magnetic charge produced in e+e- annihilations at 543-1543-1543-1GeV
Zeitschrift für Physik C Particles and Fields 38:4 (1988) 543-550
Abstract:
By seeking to identify magnetically charged particles by their trajectories in a magnetic field, we set limits on the production of monopoles and dyons, via the process e+e-→γ*→M {Mathematical expression}, of masses up to 17 GeV and of magnetic charges between 10 e and 70 e © 1988 Springer-Verlag.A study of Bhabha scattering at PETRA energies
Zeitschrift für Physik C Particles and Fields 37:2 (1988) 171-177