Model selection for $K^+\Sigma^-$ photoproduction within isobar model

TL;DR

This paper employs an isobar model with high-spin nucleon resonances and advanced regularization techniques to analyze $K^+ \Sigma^-$ photoproduction data, revealing key resonances and eliminating the need for hyperon resonances.

Contribution

It introduces a novel fitting approach using LASSO regularization and information criteria to optimize the isobar model for photoproduction data analysis.

Findings

High-spin nucleon resonances are crucial for data description.

Hyperon resonances are not necessary for a good fit.

The $N(1720)3/2^+$ resonance is particularly important.

Abstract

We utilise an isobar model to investigate the $K^+ \Sigma^-$ photoproduction off a neutron in the resonance region. Except for the Born terms, we include high-spin (spin-3/2 and spin-5/2) nucleon resonances in the consistent formalism together with a few $\Delta$ and kaon resonances to achieve an acceptable agreement with data. Interestingly, we reveal that no hyperon resonances are needed to achieve a reasonable description of data. On the other hand the $N(1720)3/2^+$ resonance was found to be very important for correct description of data. The free parameters of the model were fitted to experimental data from the LEPS and CLAS Collaborations on either differential cross sections or photon beam asymmetry. The novel feature of the fitting procedure is the use of a regularization method, the Least Absolute Shrinkage Selection Operator, and information criteria in order to choose the best fit.