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Updated: May 25, 2026

Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
Superluminal neutrinos at OPERA confront pion decay kinematics
Ramanath Cowsik1, Shmuel Nussinov, Utpal Sarkar
1Department of Physics and McDonnell Center for the Space Sciences, Washington University, St. Louis, Missouri 63130, USA.
Abstract:
Violation of Lorentz invariance (VLI) has been suggested as an explanation of the superluminal velocities of muon neutrinos reported by OPERA. In this Letter, we show that the amount of VLI required to explain this result poses severe difficulties with the kinematics of the pion decay, extending its lifetime and reducing the momentum carried away by the neutrinos. We show that the OPERA experiment limits α=(ν(ν)-c)/c<4×10(-6). We then take recourse to cosmic-ray data on the spectrum of muons and neutrinos generated in Earth's atmosphere to provide a stronger bound on VLI: (ν-c)/c<10(-12).
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