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Photoproduction of the Theta^+ resonance on the nucleon in a Regge model

H. Kwee·M. Guidal·M. V. Polyakov·M. Vanderhaeghen
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Abstract

We estimate the reaction mechanisms for the photoproduction of the Theta^+(1540) resonance on the nucleon, through K and K^* Regge exchanges. We compare the size of the cross sections for the gamma n -> K^- Theta^+ and gamma p -> K^0 bar Theta^+ reactions, and investigate their sensitivity to the spin-parity assignments J^P = 1/2^\pm, 3/2^\pm for the Theta^+ resonance. The model allows to estimate the cross sections corresponding with a given upper bound on the width of the Theta^+. Within this model, the cross sections on the neutron are found to be around a factor 5 larger than the ones on the proton, due to the presence of charged K exchange for the reaction on a neutron target. Furthermore, the photon asymmetry is found to display a pronounced sensitivity to the parity of the Theta^+, making it a very promising observable to help determining the quantum numbers of the Theta^+ resonance.

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H. Kwee, M. Guidal, M. V. Polyakov, M. Vanderhaeghen. 2005-07-25. Photoproduction of the Theta^+ resonance on the nucleon in a Regge model. https://doi.org/10.1103/physrevd.72.054012

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