TY - JOUR
T1 - A search for massive neutral bosons in orthopositronium decay
AU - Maeno, T.
AU - Fujikawa, M.
AU - Kataoka, J.
AU - Nishihara, Y.
AU - Orito, S.
AU - Shigekuni, K.
AU - Watanabe, Y.
PY - 1995/6/1
Y1 - 1995/6/1
N2 - We have searched for an exotic decay of orthopositronium into a single photon and a short-lived neutral boson in the hitherto unexplored mass region above 900 keV/c2, by noting that this decay is one of few remaining candidates which could explain the discrepancy of the orthopositronium decay rate. A high-resolution measurement of the associated photon energy spectrum was carried out with a germanium detector to search for a sharp peak from this two-body decay. Our negative result provides an upper limit of 2.0 × 10-4 on the branching ratio of such a decay in the mass region from 847 to 1013 keV/c2, and excludes the possibility of this decay mode explaining the discrepancy in the orthopositronium decay rate.
AB - We have searched for an exotic decay of orthopositronium into a single photon and a short-lived neutral boson in the hitherto unexplored mass region above 900 keV/c2, by noting that this decay is one of few remaining candidates which could explain the discrepancy of the orthopositronium decay rate. A high-resolution measurement of the associated photon energy spectrum was carried out with a germanium detector to search for a sharp peak from this two-body decay. Our negative result provides an upper limit of 2.0 × 10-4 on the branching ratio of such a decay in the mass region from 847 to 1013 keV/c2, and excludes the possibility of this decay mode explaining the discrepancy in the orthopositronium decay rate.
KW - Decay rate
KW - Exotic decay
KW - Germanium detector
KW - Neutral boson
KW - Orthopositronium decay
KW - QED
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U2 - 10.1016/0370-2693(95)00425-K
DO - 10.1016/0370-2693(95)00425-K
M3 - Article
AN - SCOPUS:0000604516
VL - 351
SP - 574
EP - 578
JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
SN - 0370-2693
IS - 4
ER -