Chiral constituent quark model study of the process γp → ηp ⋆ J. He, B. Saghai, Z. Li, Q. Zhao and J. Durand Eur. Phys. J. A, 35 3 (2008) 321-324 Published online: 24 March 2008 DOI: 10.1140/epja/i2007-10560-9