The phenomenon of the near ppˉ-threshold enhancement observed in the J/ψ → γ pp decay is studied by using the enhancement factor method with a simpler one-pion-exchange potential between p and p. The Jost function...The phenomenon of the near ppˉ-threshold enhancement observed in the J/ψ → γ pp decay is studied by using the enhancement factor method with a simpler one-pion-exchange potential between p and p. The Jost function caused by the mentioned potential is perturbatively calculated in the zero-th order approximation, and the corresponding enhancement factor is obtained. It is found that such a final state interaction offers an important contribution to the decay width near the ppˉ-threshold, although it is not large enough. To explain the decay data, a phenomenological factor G（p） with the form of 285500/（m 2 π ＋ p 2 ） should be introduced. A further calculation including the p-dependent bare T -matrix, a more realistic N ˉ N potential and the contribution from the higher-order wave functions would provide a better understanding of the decay data and even the existence of the baryonium ppˉ. The near ppˉ-threshold behavior of the decay width in the J/ψ →π 0 pp process is also discussed.展开更多
We obtain mass spectra of the light and heavy nonrelativistic potential model with Coulomb and one pion meson-antimeson （molecular states） sectors by using a exchange potential terms for meson-meson interaction. The...We obtain mass spectra of the light and heavy nonrelativistic potential model with Coulomb and one pion meson-antimeson （molecular states） sectors by using a exchange potential terms for meson-meson interaction. The digamma decay widths are also obtained for the light sector. We compare our results with available experimental and theoretical data.展开更多
基金Supported by National Natural Science Foundation of China (10675022, 10975018, 10975038, 11035006, 11165005, 11175020)Fundamental Research Funds for the Central UniversitiesKey-project by the Chinese Academy of Sciences (KJCX3-SYW-N2)
文摘The phenomenon of the near ppˉ-threshold enhancement observed in the J/ψ → γ pp decay is studied by using the enhancement factor method with a simpler one-pion-exchange potential between p and p. The Jost function caused by the mentioned potential is perturbatively calculated in the zero-th order approximation, and the corresponding enhancement factor is obtained. It is found that such a final state interaction offers an important contribution to the decay width near the ppˉ-threshold, although it is not large enough. To explain the decay data, a phenomenological factor G（p） with the form of 285500/（m 2 π ＋ p 2 ） should be introduced. A further calculation including the p-dependent bare T -matrix, a more realistic N ˉ N potential and the contribution from the higher-order wave functions would provide a better understanding of the decay data and even the existence of the baryonium ppˉ. The near ppˉ-threshold behavior of the decay width in the J/ψ →π 0 pp process is also discussed.
文摘We obtain mass spectra of the light and heavy nonrelativistic potential model with Coulomb and one pion meson-antimeson （molecular states） sectors by using a exchange potential terms for meson-meson interaction. The digamma decay widths are also obtained for the light sector. We compare our results with available experimental and theoretical data.
