English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We study first the box-diagram contribution to the $\gamma p\,\rightarrow\,K^0\Sigma^+$ process to understand the anomaly of the kaon photoproductioncross section from CBELSA/TAPS experiment at Electron Stretcher Accelerator(ELSA), where the imaginary part of the scattering amplitude from thebox-diagrams is calculated by using Cutkosky's rules in the on-shellapproximation while the real part of the amplitude is derived by dispersionrelation calculations. Together with the results of the K-MAID model, thecontribution of the box-diagrams fails to provide the sudden drop of thedifferential cross-section between the $K^*\,\Lambda$ and $K^*\,\Sigma$thresholds. In addition, we include the $\Delta(1940)$ resonance in the processto complete the description of the differential cross-section. Combining thecontributions from the K-MAID model, the box-diagrams and the $\Delta(1940)$resonance, we have obtained the theoretical differential cross-section the$\gamma p\,\rightarrow \,K^0\Sigma^+$ process, which is compatible with theCBELSA/TAPS experimental data.

Contributions of box diagrams and $\Delta(1940)$ resonance to $K^0\Sigma^+$ photoproduction