Electroproduction of the Λ/Σ0 hyperons at Q2≃0.5 (GeV/c)2 at forward angles

Abstract

In 2018, the E12-17-003 experiment was conducted at the Thomas Jefferson National Accelerator Facility (JLab) to explore the possible existence of an $nn\mathrm{\Lambda }$ state in the reconstructed missing mass distribution from a tritium gas target [K. N. Suzuki et al., Prog. Theor. Exp. Phys. 2022, 013D01 (2022); B. Pandey et al., Phys. Rev. C 105, L051001 (2022)]. As part of this investigation, data were also collected using a gaseous hydrogen target, not only for a precise absolute mass scale calibration but also for the study of $\mathrm{\Lambda }/{\mathrm{\Sigma }}^0$ electroproduction. This dataset was acquired at $Q^2\simeq 0.5$ ${(\mathrm{GeV}/c)}^2$, $W=2.14$ GeV, and ${\theta }_{\gamma \mathrm{K}}^{\mathrm{c}.\mathrm{m}.}\simeq 8^{\circ }$. It covers forward angles where photoproduction data are scarce and a low-$Q^2$ region that is of interest for hypernuclear experiments. On the other hand, this kinematic region is at a slightly higher $Q^2$ than previous hypernuclear experiments, thus providing crucial information for understanding the $Q^2$ dependence of the differential cross sections for $\mathrm{\Lambda }/{\mathrm{\Sigma }}^0$ hyperon electroproduction. This paper reports on the $Q^2$ dependence of the differential cross section for the $e+p\to e^{\prime }+K^{+}+\mathrm{\Lambda }/{\mathrm{\Sigma }}^0$ reaction at $0.2–0.8$ ${(\mathrm{GeV}/c)}^2$, and provides comparisons with the currently available theoretical models.