Strange Meson Production in Electron-Positron Annihilation at 29.0 GEV.
Neutral kaon and K*('(+OR-)) production have been studied using the PEP4 Time Projection Chamber detector facility at a 29 GeV center of mass energy. The data, corresponding to an integrated luminosity of 77 pb('-1), was taken at the Stanford Linear Accelerated Center positron -electron (PEP) storage ring. Neutral kaons were found by looking for secondary vertices in the weak decay K(,8)('0) (--->) (pi)('+)(pi)('-). The particle identification and tracking capability of the Time Projection Chamber (TPC) was used to locate secondary vertices. The K*('(+OR-)) signal was found by forming the invariant mass of (pi)('(+OR -)) with identified K(,8)('0). The resulting inclusive K('0) and K*('(+OR-)) cross sections were measured as a function of x where x = E/E(,beam). From the differential cross sections the production rate of K('0) was 1.22 (+OR -) 0.03 (+OR-) 0.15 per event. The production rate of K*('(+OR -)) was 0.414 (+OR-) 0.04 (+OR-) 0.08 per event. The differential cross sections are well described by monte carlo hadronization models. Comparison of the measured K(,8)('0) production rate with previously published (pi)('(+OR-)) results show that the production of strange mesons relative to non-strange mesons is suppressed by a factor of 0.32 (+OR-) 0.18. The K*('(+OR-)) and K('0) production rates indicate that the spin 1 to spin 0 strange meson production ratio is 0.67 (+OR-) 0.32.
- Pub Date:
- Physics: Elementary Particles and High Energy