As part of a measurement [E. Anciant et al., Phys. Rev. Lett. 85, 4682 (2000)] of the cross section of φ meson photoproduction to high momentum transfer, we measured the polar angular decay distribution of the outgoing K+ in the channel φ → K+K- in the φ center-of-mass frame (the helicity frame). We find that s-channel helicity conservation (SCHC) holds in the kinematical range where t-channel exchange dominates (up to -t ∼ 2.5 GeV2 for Eγ= 3.6 GeV). Above this momentum, u-channel production of a φ meson dominates and induces a violation of SCHC. The deduced value of the φNN coupling constant lies in the upper range of previously reported values.
ASJC Scopus subject areas
- Nuclear and High Energy Physics