ISSN:
1434-6052
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The reactione + 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 (A μμ) and cross section σμμ for this reaction at three energies. At 35.0 GeV we obtain a cross section relative to the QED prediction ofR μμ=σμμ/σo=0.932±0.018±0.044 andA μμ=(−10.6 −2.3 +2.2 ±0.5)%. At 38.3 GeV we findR μμ=0.951±0.072 −0.057 +0.063 andA μμ=(+1.7 −8.6 +8.5 ±0.5)%. At 43.6 GeV we measureR μμ=0.921±0.037±0.055 andA μμ=(−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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01555879