; Zou, Bing-Song
; Chiang, Huan-Ching] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
; [Xie, Ju-Jun
; Zou, Bing-Song] Chinese Acad Sci, Grad Inst, Beijing 100049, Peoples R China
; [Zou, Bing-Song
; Chiang, Huan-Ching] Natl Lab Heavy Ion Accelerator, Ctr Theoret Nucl Phys, Lanzhou 730000, Peoples R China
; [Chiang, Huan-Ching] SW Univ, Dept Phys, Chongqing 400071, Peoples R China
The near-threshold phi-meson production in proton-proton and pi(-)p collisions is studied with the assumption that the production mechanism is due to the sub-N phi-threshold N(*)(1535) resonance. The pi(0)-,eta-, and rho(0)-meson exchanges for proton-proton collisions are considered. It is shown that the contribution to the pp -> pp phi reaction from the t-channel pi(0)-meson exchange is dominant. With a significant N(*)(1535)N phi coupling [g(N)(*)(1535)N phi(2)/4 pi=0.13], both pp -> pp phi and pi(-)p -> n phi data are very well reproduced. The significant coupling of the N(*)(1535) resonance to N phi is compatible with previous indications of a large s (s) over bar component in the quark wave function of the N(*)(1535) resonance and may be the real origin of the significant enhancement of the phi production over the naive OZI-rule predictions.