Coupling constant forΛ(1405)K¯N

Abstract

The value of the (1405)KN coupling constant g (1405)KN is obtained by fitting it to the experimental data on the total cross sections of the K − p → π 0 0 reaction. On the basis of an effective Lagrangian approach and isobar model, we show that the value |g (1405)KN | = 1.51 ± 0.10 could be extracted from the available experimental data by assuming that the s-channel (1405) resonance plays a dominant role, whereas, the background contributions from the s-channel (1115), t-channel K * , and u-channel nucleon pole processes are small and can be neglected. However, the u-channel nucleon pole diagram may also give an important contribution in the present calculations. After the background contributions are taken into account, the above value of g (1405)KN is reduced to |g (1405)KN | = 0.77 ± 0.07, which is not supported by the previous calculations and the recent CLAS measurements. The theoretical calculations on differential cross sections are also presented, which can be checked by future experiments.

The near threshold π- p →ηn reaction in an effective Lagrangian approach

“…3, we find that the Breit-Wigner mass of N * (1535) resonance will be pushed down if we use the energy-dependent width, which is similar to the case of Λ(1405) state that we found in Ref. [31]. This will have important implications on various model calculations on the mass of N * (1535) resonance [7][8][9].…”

Role of Λ(1670) in the γp → K+ ηΛ reaction near threshold

“…We study the γp → K + ηΛ reaction within an effective Lagrangian approach and the isobar model, which has been successfully used in our previous work [14][15][16][17][18][19][20]. The basic Feynman diagrams for this process are depicted in Fig.…”

Nucleon resonances in theγp→ϕK+Λreaction near threshold

“…We study the γp → φK + Λ reaction near threshold within an effective Lagrangian approach and the isobar model, which has been extensively applied to the study of scattering processes [26][27][28][29][30][31][32][33][34][35][36][37]. The basic tree level Feynman diagrams for the γp → φK + Λ reaction are depicted in Fig.…”

“…The coupling constants in the above Lagrangian densities are taken as [7,31,35]: g πN N = 13.45, g KN Λ = −13.98, and g ηN N = 2.24.…”