Phi Meson and Accompanying Strange Particle Production in 16 Gev/c Positive-Pi Interactions.
We have studied (phi) production in 16 GeV/c (pi)('+)p interactions. K('-) identified in a Cerenkov counter were used to trigger the Stanford Linear Accelerator Center 2-meter streamer chamber. A sample of inclusive (phi) events was thus obtained where (phi) (--->) K('-)K('+). Information from a second Cerenkov counter was used to identify the K('+) off-line. In addition, the visible decays in the streamer chamber of (LAMDA)(DEGREES) (--->) p(pi)('-) and K(,s)(DEGREES) (--->) (pi)('+)(pi)('-) were used to obtain events of the type (pi)('+)p (--->) (phi)(LAMDA)(DEGREES) + anything and (pi)('+)p (--->) (phi) K(,s)(DEGREES) + anything. With 1.26 x 10('9) (pi)('+) onto a 61 cm liquid hydrogen target, the experiment had a raw sensitivity of 3.1 events/nb. For the film measured so far, taking into account geometric acceptance, unseen decay modes, and all efficiency corrections, the sensitivities are 7.1 events/(mu)b, 22 events/(mu)b, and 27 events/(mu)b respectively for the (phi) inclusive, (phi) with (LAMDA)(DEGREES), and (phi) with K(,s)(DEGREES) samples. The acceptance covers the region in Feynman's x, x(,(phi)) > 0.5. The measured cross sections for x(,(phi)) > 0.5 are (sigma)((phi) + X) = 1.3 (+OR-) 2.0 (mu)b, (sigma)((phi)(LAMDA)(DEGREES) + X) = 0.37 (+OR-) 0.16 (mu)b, and (sigma)((phi)K(,s)('(DEGREES)) + X) = 0.33 (+OR-) 0.15 (mu)b. When account is taken of unseen associated channels, it is concluded that (phi) is predominanly produced conjointly with pairs of strange particles. This agrees with the OZI rule, and is consistent with (phi) being produced by a quark fusion type process, rather than gluon fusion or light quark annihilation.
- Pub Date:
- March 1982
- Physics: Elementary Particles and High Energy