Combined study of {gamma}p{yields}{eta}p and {pi}{sup -}p{yields}{eta}n in a chiral constituent quark approach

Within a chiral constituent quark model approach, {eta}-meson production on the proton via electromagnetic and hadron probes is studied. With few parameters, the differential cross section and polarized beam asymmetry for {gamma}p{yields}{eta}p and differential cross section for {pi}{sup -}p{yields}{eta}n processes are calculated and successfully compared with the data in the center-of-mass energy range from threshold up to 2 GeV. The five known resonances S{sub 11}(1535), S{sub 11}(1650), P{sub 13}(1720), D{sub 13}(1520), and F{sub 15}(1680) are found to be dominant in the reaction mechanisms in both channels. Possible roles played by new resonances are also investigated; and in the photoproduction channel, significant contribution from S{sub 11} and D{sub 15} resonances, with masses around 1715 and 2090 MeV, respectively, are deduced. For the so-called missing resonances, no evidence is found within the investigated reactions. The helicity amplitudes and decay widths of N*{yields}{pi}N, {eta}N are also presented and found to be consistent with the Particle Data Group values.