Photoproduction of neutral kaons on a liquid deuterium target in the threshold region

The photoproduction process of neutral kaons on a liquid deuterium target is investigated near the threshold region, ${E}_{\ensuremath{\gamma}}=0.8\text{\ensuremath{-}}1.1$ GeV. ${K}^{0}$ events are reconstructed from positive and negative pions, and differential cross sections are derived. Experimental momentum spectra are compared with those calculated in the spectator model using a realistic deuteron wave function. Elementary amplitudes as given by recent isobar models and a simple phenomenological model are used to study the effect of the new data on the angular behavior of the elementary cross section. The data favor a backward-peaked angular distribution of the elementary $n(\ensuremath{\gamma},{K}^{0})\ensuremath{\Lambda}$ process, which provides additional constraints on current models of kaon photoproduction. The present study demonstrates that the $n(\ensuremath{\gamma},{K}^{0})\ensuremath{\Lambda}$ reaction can provide key information on the mechanism of the photoproduction of strangeness.