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The polarization of $\mathrm{\Lambda }$ hyperons is preserved in the angular distribution of their decay products. This property allows one to study the spin structure of the $\mathrm{\Lambda }$ . In semi-inclusive deep inelastic scattering where a high energy lepton interacts with a nucleon target and one or more hadrons and the scattered lepton are detected in the final state, the probability for a struck quark to impart the polarization of the lepton to the $\mathrm{\Lambda }$ may be measured. In particular, in electron-proton scattering this quantity may be related to the longitudinal light quark polarization of the $\mathrm{\Lambda }$ . Currently, limited experimental data cannot discriminate between different models of $\mathrm{\Lambda }$ spin structure. This work reports on the measurement of the longitudinal spin transfer $D_{L{L}^{\prime }}^{\mathrm{\Lambda }}$ to the $\mathrm{\Lambda }$ using data taken by the CLAS12 spectrometer at Jefferson Lab with a 10.6 GeV longitudinally polarized electron beam and an unpolarized hydrogen target. This measurement is the most precise to date, and, in comparison with theory predictions, it offers valuable insight into the relative dominance of current and target fragmentation in $\mathrm{\Lambda }$ production. 

We present measurements of the total and differential cross sections for near-threshold $J/\psi$ photoproduction obtained with the CLAS12 detector at the Thomas Jefferson National Accelerator Facility. The results are based on data collected during the fall 2018 and spring 2019 running periods, using electron beams with energies of 10.6 and 10.2 GeV, respectively, scattered off a liquid-hydrogen target. Near-threshold $J/\psi$ photoproduction offers a unique sensitivity to the strong interaction in the nonperturbative regime of quantum chromodynamics (QCD). The energy dependence of the cross section constrains the underlying $J/\psi$ production mechanisms, including multigluon exchange and potential baryonic excitations. Additionally, the $t$ dependence of the differential cross section can be related to the transverse spatial distribution of gluons in the proton, providing critical input for theoretical descriptions of the gluonic structure of the proton. An interpretation of the results in terms of the gluon content of the proton is presented, providing new experimental constraints on QCD-inspired models of the proton structure and the role of gluonic degrees of freedom in hadronic mass generation.