Separated Structure Functions for the Exclusive Electroproduction of $K^+\Lambda$ and $K^+\Sigma^0$ Final States

TL;DR

This paper presents the first separated structure functions for exclusive $K^+\Lambda$ and $K^+\Sigma^0$ electroproduction, providing detailed insights into the production dynamics across a broad kinematic range.

Contribution

It introduces the first $ ext{σ}_L/ ext{σ}_T$ separation with CLAS and measures structure functions away from parallel kinematics, enhancing understanding of hyperon production mechanisms.

Findings

Distinct production dynamics for $ ext{Λ}$ and $ ext{Σ}^0$ hyperons

Broad kinematic coverage of $Q^2$ and $W$

Data constrains models of strangeness production

Abstract

We report measurements of the exclusive electroproduction of $K^+\Lambda$ and $K^+\Sigma^0$ final states from a proton target using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The separated structure functions $\sigma_T$, $\sigma_L$, $\sigma_{TT}$, and $\sigma_{LT}$ were extracted from the $\Phi$- and $\epsilon$-dependent differential cross sections taken with electron beam energies of 2.567, 4.056, and 4.247 GeV. This analysis represents the first $\sigma_L/\sigma_T$ separation with the CLAS detector, and the first measurement of the kaon electroproduction structure functions away from parallel kinematics. The data span a broad range of momentum transfers from $0.5\leq Q^2\leq 2.8$ GeV$^2$ and invariant energy from $1.6\leq W\leq 2.4$ GeV, while spanning nearly the full center-of-mass angular range of the kaon. The separated structure functions reveal clear differences between the production dynamics for the $\Lambda$ and $\Sigma^0$ hyperons. These results provide an unprecedented data sample with which to constrain current and future models for the associated production of strangeness, which will allow for a better understanding of the underlying resonant and non-resonant contributions to hyperon production.