We report an improved measurement of the inverse muon decay process, ν μ +e→ μ − + ν e , at the Fermilab Tevatron. The rate of this reaction with respect to the ν μ -N charged current interaction is measured to be (0.1245±0.0057(stat.)±0.0031 (sys.)) × 10 −2 . The measurement confirms the standard model predictions for the Lorentz structure of the weak current, the helicity of the neutrino, and the energy dependence of the cross section.
Data from the Quadruple Triplet Neutrino beam (QTB).
Data from the Narrow Band Beam(NBB).
Weighted average of the QTB and NBB data.
We investigate the four-photon final state produced in γγ colissions. In the π 0 π 0 channel we observe f(1270) production with predominantly helicity 2 and measure a partial width Γ γγ 2.9 +0.6 −0.4 ± keV (independent of assumptions on the helicity). We observe A 2 (1310) production in the π 0 η channel and find a partial width Γ γγ = 0.77 ± 0.18 ± 0.27 KeV (assuming helicity 2). We give an upper limit for f ≈ ηη .
Data read from graph. Systematic error on M is of order of 2% or less.
Data read from graph.
No description provided.
Muon-neutrino and -antineutrino scattering off electrons was detected in a 19-ton Al spark chamber, exposed to the wide-band ν (ν¯) beam from the CERN proton synchrotron. The background was determined experimentally. 11 (10) genuine νμ− (ν¯μ−) e scattering events were found. The respective cross sections are (1.1±0.6)×10−42(Eν/GeV) cm2 and (2.2±1.0)×10−42(Eν/GeV) cm2. The analysis excludes a pure V−A interaction, and makes a pure V or A theory improbable. The data agree well with the Salam-Weinberg model and sin2θW=0.35±0.08.
No description provided.
No description provided.