η′ photoproduction near threshold

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In this work, the η′ meson photoproduction near threshold is studied in the quark model framework. A pseudovector effective Lagrangian is introduced for the η′ NN coupling and the newly published data from the SAPHIR Collaboration provide good constraints to this parameter. Corrections of order O(1/mq²) for the electromagnetic interaction vertex are taken into account, which produce corrections of order O(1/mq³) to the transition amplitude for γp→ η′ p. Some low-lying resonances, S₁₁(1535), P₁₃(1720), and P₁₃(1900) are found to have significant contributions. A bump structure around Eγ≈ 2 GeV is found arising from the n=3 terms in the harmonic oscillator basis. The beam polarization asymmetries are predicted and can be tested against the forthcoming data from GRAAL.