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Bayesian Model Selection for Electromagnetic Kaon Production on the Nucleon

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 نشر من قبل Lesley De Cruz
 تاريخ النشر 2011
  مجال البحث
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We present the results of a Bayesian analysis of a Regge model for K+ Lambda photoproduction. The model is based on the exchange of K+(494) and K*+(892) trajectories in the t-channel. For different prior widths, we find decisive Bayesian evidence (Delta ln Z ~ 24) for a K+ Lambda photoproduction Regge model with a positive vector coupling and a negative tensor coupling constant for the K+(892) trajectory, and a rotating phase factor for both trajectories. Using the chi^2 minimization method, one could not draw this conclusion from the same dataset.



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We present the results of a Bayesian analysis of a Regge model to describe the background contribution for K+ Lambda and K+ Sigma0 photoproduction. The model is based on the exchange of K+(494) and K*+(892) trajectories in the t-channel. We utilise t he Bayesian evidence Z to determine the best model variant for each channel. The Bayesian evidence integrals were calculated using the Nested Sampling algorithm. For different prior widths, we find decisive Bayesian evidence (Delta ln Z ~ 24) for a K+ Lambda photoproduction Regge model with a positive vector coupling and a negative tensor coupling constant for the K*+(892) trajectory, and a rotating phase factor for both trajectories. Using the chi^2 minimisation method, one could not draw this conclusion from the same dataset. For the K+ Sigma0 photoproduction Regge model, on the other hand, the difference between the evidence integrals is insufficient to pinpoint one model variant.
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