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Attempts at explaining the NuTeV observation of dimuon events.

Dedes, Athanasios; Dreiner, Herbi; Richardson, Peter


Athanasios Dedes

Herbi Dreiner


The NuTeV Collaboration has observed an excess in their dimuon channel, possibly corresponding to a long-lived neutral particle with only weak interactions and which decays to muon pairs. We show that this cannot be explained by pair production of neutralinos in the target followed by their decay far downstream in the detector via a LLE R-parity violating operator, as suggested in the literature. In the parameter region allowed by the CERN e+e− collider LEP the event rate is far too small. We propose instead a new neutralino production method via B mesons, which can fully explain the observation. This is analogous to neutrino production via π mesons. This model can be completely tested and thus also possibly excluded with NOMAD data. If it is excluded, the NuTeV observation is most likely not due to physics beyond the standard model. Our model can also be tested at the current and future B factories. This opens up a new way of testing for a long-lived neutralino lightest supersymmetric particle at fixed-target experiments and thus the possibility of closing the gap between collider and cosmological tests of R-parity violation. We also discuss a possible explanation in terms of a neutral heavy lepton mixing with the standard model neutrinos. The flavor structure of the observation can be accounted for but the production rate is far too low.


Dedes, A., Dreiner, H., & Richardson, P. (2002). Attempts at explaining the NuTeV observation of dimuon events. Physical Review D, 65(1), Article 015001.

Journal Article Type Article
Publication Date 2002-01
Journal Physical Review D
Print ISSN 2470-0010
Electronic ISSN 2470-0029
Publisher American Physical Society
Peer Reviewed Peer Reviewed
Volume 65
Issue 1
Article Number 015001