Near threshold angular distributions for the 2H(γ, λ)X reaction

Abstract

A study of the 2H(γ, λ)X reaction was performed using a tagged photon beam at the Research Center for Electron Photon Science (ELPH), Tohoku University. The photoproduced λ was measured in the pφ decay channel by the upgraded Neutral Kaon Spectrometer (NKS2+). The momentum integrated differential cross section was determined as a function of the scattering angle of λ in the laboratory frame for five energy bins. Our results indicated a peak in the cross section at angles smaller than cos θ LAB λ = 0.96. The experimentally obtained angular distributions were compared to isobar models, Kaon-Maid (KM) and Saclay-Lyon A (SLA), in addition to the composite Regge-plus-resonance (RPR) model. Both SLA(rK1Kγ =.1.4) and RPR describe the data quite well in contrast to the KM model, which substantially under-predicted the cross section at the most forward angles. With the anticipated finalized data on λ integrated and momentum dependent differential cross sections of 2H(γ, λ) X [M. Kaneta et al., Nucl. Phys. A 914, 69 (2013)], we present our findings on the angular distributions.