φ production in [formula omitted] annihilation at rest

Abstract

We report on measurements of the branching ratios for φ production in pp annihilation at rest in H 2 gas. Branching ratios for φπ 0, φη, φϱ 0, φω and φπ + π − are determined for two data sets with different contributions of annihilations from S and P states of the pp system. The branching ratios are compared to corresponding annihilation modes where the φ is replaced by an ω meson. We conclude that φ production is in most reactions enhanced with respect to the expectation based on the OZI rule. In annihilations from the spin triplet ground state of antiprotonic hydrogen into φπ the OZI rule is violated dramatically.