| Página principal > The KARMEN time anomaly |
| Article | |
| Title | The KARMEN time anomaly : search for a neutral particle of mass 339 Me V in pion decay |
| Author(s) | Kettle, P R ; Daum, M ; Janousch, M ; Koglin, J ; Pocanic, D ; Schottmüller, J ; Wigger, C ; Zhao, Z G |
| Affiliation | (Paul Scherrer Inst, Villigen, Switzerland) |
| Publication | 2001 |
| In: | 30th International Conference on High-energy Physics, Osaka, Japan, 27 Jul - 2 Aug 2000, pp.1177-9 (vol.2) |
| Subject category | Particle Physics - Phenomenology |
| Abstract | We have searched the muon momentum spectrum from pion decay-in-flight for evidence of a hitherto unknown neutral particle X, with a mass of 33.905 MeV. This process was suggested by the KARMEN collaboration as an explanation for a 'long-standing' anomaly in their data of neutrino induced reactions originating from stopped pion and muon decays. Using the advantages of a decay-in-flight experiment to kinematically separate muons associated with an X-particle from those originating from normal pion decay, we find no evidence for such a process and place an upper limit on the branching fraction eta <or= 6.0.10/sup -10 / of such decays at a confidence level of 95%. |