Measurement of the energy spectrum of νe from muon decay and implications for the Lorentz structure of the weak interaction
KARMEN group, B. Armbruster, I. M. Blair, B. A. Bodmann, N. E. Booth, G. Drexlin, V. Eberhard, J. A. Edgington, C. Eichner, K. Eitel, E. Finckh, H. Gemmeke, J. Hößl, T. Jannakos, P. Jünger, M. Kleifges, J. Kleinfeller, W. Kretschmer, R. Maschuw, C. Oehler, P. Plischke, J. Rapp, C. Ruf, M. Steidl, O. Stumm, J. Wolf, B. Zeitnitz
Abstract
The KARMEN experiment uses the reaction 12C(νe,e-)12N to measure the energy distribution of νe emitted in muon decay at rest. The νe analog ωl of the famous Michel parameter ρhas been derived from a maximum-likelihood analysis of events near the kinematic end point, Emax. The result, ωl = (2.7+3.8-3.3 3.1) * 10-2, is in good agreement with the standard model prediction ωl= 0. We deduce a 90% confidence upper limit of ωl <= 0.113, which corresponds to a limit of |gSRL + 2 gTRL| <= 0.78 on the interference term between scalar and tensor coupling constants.
Create a lesson
Related papers
Operational Challenges in Efficient and Sustainable Operation of the Event Processing Nodes GPU Farm at the ALICE Experiment
Federico Ronchetti, Giada Erba
Measurements of isolated photon pair production in association with jets in pp collisions at s = 8 TeV with the ATLAS detector
ATLAS Collaboration
Projected sensitivity of the detector to photophobic and fermion-coupled axion-like particles
Riley Aumonier, Oleg Brandt, Theo Reymermier et al.
Search for heavy neutral leptons in top quark decays with same-sign, same-flavor dilepton final states in proton-proton collisions at s = 13 TeV
CMS Collaboration
A New Precise Measurement of the e+e-π+π-(γ) Cross Section with the Initial-State Radiation Method at BaBar
BaBar Collaboration
A New Precise Measurement of the e+e-π+π-(γ) Cross Section with the Initial-State Radiation Method at BaBar
BaBar Collaboration