Details

Autor(en) / Beteiligte

• Meijer Drees, R.
• Waltham, C.
• Bernasconi, T.
• Egli, S.
• Hermes, E.
• Muheim, F.
• Niebuhr, C.
• Pruys, H.
• van der Schaaf, A.
• Bertl, W.
• Grossmann-Handschin, M.
• Lordong, N.
• Vermeulen, D.
• Walter, H.K.
• Eichler, R.
• Felawka, L.
• Kozlowski, T.
• Playfer, S.
• Martino, J.

Titel

Search for weakly interacting neutral bosons produced in. pi. sup minus p interactions at rest and decaying into e sup + e minus pairs

Ist Teil von

• Physical review letters, 1992-06, Vol.68:26

Ort / Verlag

United States

Erscheinungsjahr

1992

Quelle

PROLA (Physical Review Online Archive)

Beschreibungen/Notizen

• We present the result of a search for weakly interacting neutral bosons ({ital X}) produced in {pi}{sup {minus}}{ital p} interactions at rest and decaying into {ital e}{sup +}{ital e{minus}} pairs. The data sample searched contains 98 400 {pi}{sup 0}{r arrow}{ital e}{sup +}{ital e{minus}}{gamma} decays and 27 200 {pi}{sup {minus}}{ital p}{r arrow}{ital ne}{sup +}{ital e{minus}} events, each with an {ital e}{sup +}{ital e{minus}} invariant mass between 25 and 139 MeV/{ital c}{sup 2}. They were observed in the SINDRUM I magnetic spectrometer at the Paul Scherrer Institute (Switzerland). We measure upper limits for the branching ratios {Gamma}({pi}{sup 0}{r arrow}{ital X}{gamma}, {ital X}{r arrow}{ital e}{sup +}{ital e{minus}})/{Gamma}({pi}{sup 0}{r arrow}all) and {Gamma}({pi}{sup {minus}}{ital p}{r arrow}{ital Xn}, {ital X}{r arrow}{ital e}{sup +}{ital e{minus}})/{Gamma}({pi}{sup {minus}}{ital p}{r arrow}all) for {ital X} lifetimes between 10{sup {minus}23} and 10{sup {minus}11} s.