## Abstract

pp annihilation into mesons in flight and at rest are analysed in the constituent quark model with the ^{3}P_{0} and the ^{3}S_{1} model for the qq pair creation/annihilation vertex. In the ^{3}P_{0} model, one assumes that the created/annihilated qq pair has the quantum number of the vacuum, while in the ^{3}S_{1} model, it has the quantum number of a gluon. As the meson channels we consider combinations of s-wave mesons and p-wave mesons, and in the annihilation into two mesons we compare the annihilation model (A2), the rearrangement model with a ^{3}P_{0} vertex (R2) and the rearrangement with a ^{3}S_{1} vertex (S2). The initial state interaction is taken into account by solving the coupled Lippmann-Schwinger equation including virtual NΔ ± NΔ and ΔΔ channels. The combination of R3 and A2 in the ^{3}P_{0} model roughly reproduces the branching ratios of pp annihilation into mesons, while the combination of R3 and R2 and the combination of R3 and S2 show worse agreement with the experimental branching ratios. The total pp annihilation cross section turned out to be about 60% of the experimental value for R3 + A2 and R3 + R2 and about 70% for R3 + S2, which means that we need other mechanisms of pp annihilation into mesons. The channel of virtual Δ's modifies the branching ratios of certain partial waves, but in the total annihilation cross section, the effect of Δ's is not large.

Original language | English |
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Pages (from-to) | 643-700 |

Number of pages | 58 |

Journal | Nuclear Physics, Section A |

Volume | 472 |

Issue number | 4 |

DOIs | |

Publication status | Published - 1987 Oct 12 |

Externally published | Yes |

## ASJC Scopus subject areas

- Nuclear and High Energy Physics