English

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

Nuclear Theory 2009-11-10 v3 Nuclear Experiment

Abstract

The problem of extracting information on new and known NN^{*} 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+)Λp(\gamma,K^{+})\Lambda 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 P11P_{11} resonance, with a mass of about 1.9 GeV, gives the best agreement with the published data, but additional S11S_{11} or D13D_{13} resonances cannot be ruled out. Our genetic algorithm method predicts that photon beam asymmetry and double polarization p(γ,K+)Λp(\gamma,K^{+})\Lambda measurements should provide the most sensitive information with respect to missing resonances.

Keywords

Cite

@article{arxiv.nucl-th/0312103,
  title  = {A Genetic Algorithm Analysis of N* Resonances in $p(\gamma,K^{+})\Lambda$ Reactions},
  author = {D. G. Ireland and S. Janssen and J. Ryckebusch},
  journal= {arXiv preprint arXiv:nucl-th/0312103},
  year   = {2009}
}

Comments

34 pages, 11 figures; Revised version accepted for publication by Nuclear Physics A

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