π +π -π o and ππγ production by e +e - annihilation in the φ energy range with the Orsay storage ring
Abstract
A large solid angle detector has been used to observe π +π -π o events produced at the φ energy by electron-positron collisions in the Orsay storage ring. Fitting our data with a Breit and Wigner curve, with a fixed width Γ = (3.8±0.4) MeV coming from K OSK OL analysis, we deduce σe+e-→ π+π-πO = (0.70±0.13) μbat 2 E = Mφ. Using our measurements on the other φ decay modes we deduce ( φ→ π+π-πo)/( φ→ KoSKoL) = 0.47±0.06 and ( φ→ ηoγ)/( φ→ KoSKoL) = 0.077±0.022. Assuming ( φ→ K+K-)/( φ→ KoSKoL) = 1.60, we derive σTOT = (4.7±0.4) μb, Γe+e-= (1.27±0.11 keV and g2o/4 π = 14.3±1.3 (without finite width correction). Furthermore (from the observation of the ππγ coplanar events) we put an upper limit to the mode e+e- → φπ+π-γ, Γ( φ → π+π-γ) ⩽ 0.007 Γ( φ→ Total) with 90% C.L.
- Publication:
-
Physics Letters B
- Pub Date:
- January 1974
- DOI:
- 10.1016/0370-2693(74)90667-4
- Bibcode:
- 1974PhLB...48..155C