Determination of the polarization observables $C_{x}$, $C_{z}$, and $P$ for the $\vec{\gamma}d\to K^{0}\Lambda(p)$ reaction

TL;DR

This paper reports preliminary measurements of polarization observables in kaon-hyperon photoproduction off the deuteron, providing new data crucial for understanding nucleon resonances and neutron interactions.

Contribution

It presents the first polarization observables for the reaction $oldsymbol{\gamma d o K^{0}\Lambda(p)}$, expanding data for neutron-targeted meson photoproduction.

Findings

Measured $P$, $C_x$, $C_z$ observables across 0.9-2.6 GeV photon energies.

Data covers a wide angular range with implications for nucleon resonance studies.

Discussed the influence of neutron binding on polarization observables.

Abstract

Many excited nucleon states ($N^{*}$s) predicted by quark models, but not observed in $\pi N$ channels, are expected to couple strongly to kaon--hyperon ($KY$) channels. While in the last decade data have been published for $KY$ photoproduction off the proton, data off the neutron are scarce. In this paper we present preliminary results for the polarization observables $P$, $C_x$, and $C_z$ for the reaction $\gamma d\to K^{0}\Lambda(p)$, where $(p)$ denotes the spectator proton. The observables cover photon energies, $E_{\gamma}$, between 0.9 GeV and 2.6 GeV and kaon center-of-mass angles, cos$\theta_{K^{0}}^{CM}$, between $-0.9$ and 1. The data were collected in experiment E06-103 (g13) with the CLAS detector at the Thomas Jefferson National Accelerator Facility using a circularly-polarized photon beam and an unpolarized liquid deuterium target. We also discuss the effect of neutron binding on the observables. Our study is part of a broader effort by the g13 group to provide cross sections and polarization observables for meson photoproduction off the neutron and is expected to have a significant impact on the $N^{*}$ research.