Recoil Polarization in $K^+Y$ Electroproduction in the Nucleon Resonance Region with CLAS12

TL;DR

This paper reports new recoil polarization measurements in $K^+Y$ electroproduction using CLAS12, providing extensive data across various energies and angles to better understand strangeness production and nucleon structure.

Contribution

It presents the first electroproduction measurements of $ ext{Sigma}^0$ recoil polarization and extends existing $ ext{Lambda}$ data with a larger dataset across a broad kinematic range.

Findings

Extended $ ext{Lambda}$ polarization data over a larger dataset.

First measurements of $ ext{Sigma}^0$ recoil polarization in electroproduction.

Data will improve understanding of reaction mechanisms and nucleon resonance spectrum.

Abstract

Hyperon recoil polarization measurements for the exclusive electroproduction of $K^+\Lambda$ and $K^+\Sigma^0$ final states from an unpolarized proton target have been carried out using the CLAS12 spectrometer at Jefferson Laboratory. The measurements at beam energies of 6.535~GeV and 7.546~GeV span the range of four-momentum transfer $Q^2$ from 0.3 to 4.5~GeV$^2$ and invariant mass $W$ from 1.6 to 2.4~GeV, while covering the full center-of-mass angular range of the $K^+$. These new $\Lambda$ polarization observables extend the existing data in a similar kinematic range but from a significantly larger dataset. However, they represent the first electroproduction measurements of this observable for the $\Sigma^0$. These data will allow for better exploration of the reaction mechanism in strangeness production, for further understanding of the spectrum and structure of excited nucleon states that couple to $KY$, and for improved insight into the strong interaction in the non-perturbative domain.