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A Genetic Algorithm Analysis of N* Resonances in $p(γ,K^{+})Λ$ Reactions

D. G. Ireland·S. Janssen·J. Ryckebusch
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Abstract

The problem of extracting information on new and known $N^{*}$ resonances by fitting isobar models to photonuclear data is addressed. A new fitting strategy, incorporating a genetic algorithm, is outlined. As an example, the method is applied to a typical tree-level analysis of published $p(γ,K^{+})Λ$ data. It is shown that, within the limitations of this tree-level analysis, a resonance in addition to the known set is required to obtain a reasonable fit. An additional $P_{11}$ resonance, with a mass of about 1.9 GeV, gives the best agreement with the published data, but additional $S_{11}$ or $D_{13}$ resonances cannot be ruled out. Our genetic algorithm method predicts that photon beam asymmetry and double polarization $p(γ,K^{+})Λ$ measurements should provide the most sensitive information with respect to missing resonances.

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D. G. Ireland, S. Janssen, J. Ryckebusch. 2004-05-13. A Genetic Algorithm Analysis of N* Resonances in $p(γ,K^{+})Λ$ Reactions. https://doi.org/10.1016/j.nuclphysa.2004.05.007

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