Coupling strength of theN*(1535)S11to theK+Λc

Abstract

The N * (1535)S 11 coupling strength to the K + Λ channel, g N * (1535)ΛK + , is extracted from the latest and largest K + Λ photoproduction database by using an isobar model. It is found that the coupling is small. In term of the coupling ratio the best result is R ≡ |g N * (1535)ΛK + /g N * (1535)ηp | = 0.460 ± 0.172, much smaller than that obtained from the isobar analysis of the J/ψ decays, i.e., 1.3 ± 0.3, but consistent with the results of the unitary chiral approach of the same decay processes as well as the partial wave analysis of kaon photoproduction, i.e., R = 0.5 ∼ 0.7. The different results of R found here and in literature to date suggest that a more solid definition of the coupling constant, especially in the case of N * (1535)S 11 state, is urgently required, before a fair comparison can be made.

Partial wave analysis for KΣ photoproduction on the nucleon valid from threshold up to W = 2.8 GeV

“…Note that this value is slightly different from that obtained in our previous work [80] due to the different value of A p 1 2 obtained from the recent PDG estimate [1]. By using this new value we obtain R Λ =0.360±0.076 , instead of 0.460±0.172 [80]. On the other hand, the value of…”

“…Since the N(1535)S 11 is a negative-parity state, the relation between the amplitude and the electromagnetic coupling reads [83] . Note that this value is slightly different from that obtained in our previous work [80] due to the different value of A p 1 2 obtained from the recent PDG estimate [1]. By using this new value we obtain R Λ =0.360±0.076 , instead of 0.460±0.172 [80].…”

“…does not change, i.e. 1.853±0.244 [80]. Nevertheless, the previous conclusion remains unchanged, i.e.…”

“…coupling in the g +  + L + p K photoproduction channel by exploiting a covariant isobar model [80]. Although the analysis was performed in a single channel framework, it used the largest L + K photoproduction database.…”

“…coupling constant is undetermined from the corresponding branching ratio [see equation (5) of [80]].…”