Constituent-counting rule in photoproduction of hyperon resonances

Understand

We analyze the CLAS data on the photoproduction of hyperon resonances, as well as the available data for the ground state $\Lambda$ and $\Sigma ^{0}$ of the CLAS and SLAC-E84 collaborations, by considering constituent-counting rule suggested by perturbative QCD.

• The counting rule emerges as a scaling behavior of cross sections in hard exclusive reactions with large scattering angles, and it enables us to determine the number of elementary constituents inside hadrons.
• Therefore, it could be used as a new method for identifying internal constituents of exotic-hadron candidates.
• From the analyses of the $\gamma \, p \to K^{+} \Lambda$ and $K^{+} \Sigma ^{0}$ reactions, we find that the number of the elementary constituents is consistent with $n_{\gamma} = 1$, $n_{p} = 3$, $n_{K^{+}} = 2$, and $n_{\Lambda} = n_{\Sigma ^{0}} = 3$.