Abstract
We have searched for the exotic annihilation of orthopositronium: e+e−(3S1)→γ+a, where a is a light neutral pseudoscalar. The upper limit on the ratio of this decay rate to the 3γ decay rate obtained is Γ(o-Ps→γ+a)/Γ(o-Ps→3γ)<3.8×10−4 (90% CL), if the mass ma<30 keV. This result excludes the hypothesis of Samuel that this decay may resolve the discrepancy between the theoretical and experimental values of the orthopositronium lifetime in vacuum if the a mass is under 5.7 keV.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
