Thepp→pΛK+andpp→pΣ0K+

Abstract

We report on a theoretical study of the pp → pΛK + and pp → pΣ 0 K + reactions near threshold using a chiral dynamical approach. The production process is described by single-pion and singlekaon exchange. The final state interactions of nucleon-hyperon, K-hyperon and K-nucleon systems are also taken into account. We show that our model leads to a fair description of the experimental data on the total cross section of the pp → pΛK + and pp → pΣ 0 K + reactions. We find that the experimental observed strong suppression of Σ 0 production compared to Λ production at the same excess energy can be explained. However, ignorance of phases between some amplitudes does not allow to properly account for the nucleon-hyperon final state interaction for the pp → pΣ 0 K + reaction. We also demonstrate that the invariant mass distribution and the Dalitz plot provide direct information about the Λ and Σ 0 production mechanism, and may be tested by experiments at COSY or HIRFL-CSR.

Role of the possibleΣ*(12−)state in theΛp→Λp

“…Indeed, as pointed in Ref. [31], only two parameters in the Λp interaction are enough to reproduce the current experimental data on low energy Λp scattering.…”

“…Thus, to analyze the low energy elastic Λp → Λp transition cross section, we need four parameters: scattering length a s and effective range r s for the spin of Λp system S Λp = 0; scattering length a t and effective range r t for S Λp = 1. However, the current lower energy experimental data on the Λp → Λp reaction and pp → ΛpK + reaction only support the determination of a spin-averaged scattering lengthā and effective ranger [28][29][30][31]. Indeed, as pointed in Ref.…”

Role of theN*(2080)inpp→pK+Λ(Xie1, Liu2 2013Phys. Rev. CSelf Cite396610View full textAdd to dashboardCite

“…Λ(1520)p final-state-interaction (FSI), which can increase the results even by a factor of 10 at the very near threshold region, such as the important role played by Λp FSI in the pp → pK + Λ reaction [39]. This is because there are no experimental data on this reaction and also very scarce information about the Λ(1520)p FSI.…”

Nucleon resonances in πN → η′N and J/ψ → pp̄η′

“…In recent years, plenty of information on nucleon resonances [1] has been obtained by a wealth of phenomenological studies on numerous data of the πN , γN , eN reactions and pN collisions [23][24][25][26][27][28][29][30][31][32][33][34][35]. However, despite a great deal of theoretical and experimental efforts, our knowledge of nucleon resonances around 2.0 GeV is still scarce because of the presence of many resonances and opening channels in this energy region.…”

“…Unfortu- * Electronic address: caoxu@impcas.ac.cn † Electronic address: xiejujun@impcas.ac.cn nately, up to date we know little about the coupling of the η ′ -, ω-, and φ-mesons to nucleon resonances [50] and the interaction of these mesons with the nucleon [51]. In past decades, the production of these mesons in the γN and pN reactions have been widely investigated, mainly motivated by the increasing data measured by CLAS, CBELSA and COSY groups [24][25][26][27][28][29][30][31][52][53][54]. But the results are quite inconclusive for the moment.…”