论文部分内容阅读
We re-study nucleon pole contribution in J/ψ→NNπ decays by including the imaginary part for the propagator of the off-shell nucleon with energy above πN threshold. It is found that when including the imaginary part in the propagator, the branching ratio of the decay width will descend about 11% compared with the result without including the imaginary part, no matter whether including the off-shell form factors or not. It also leads to a phase of up to 25° for the off-shell nucleon propagator at invariant mass around 1400 MeV. This effect needs to be considered for detailed partial wave analysis of N* resonances around this mass region.
We re-study nucleon pole contribution in J / ψ → NNπ decays by including the imaginary part for the propagator of the off-shell nucleon with energy above πN threshold. It is found that when including the imaginary part in the propagator, the branching ratio of the decay width will descend about 11% compared with the result without including the imaginary part, no matter whether including the off-shell form factors or not. It also leads to a phase of up to 25 ° for the off-shell nucleon propagator at invariant mass around 1400 MeV. This effect needs to be considered as detailed partial wave analysis of N * resonances around this mass region.