The strangeness photoproduction processes near the threshold have been intensively studied by measuring K+ in reactions such as γ+p→K++Λ(Σ0). There has been no reliable data on the neutron and as a ...consequence theoretical investigation suffered seriously from the lack of the data. We have an effort to measure the γ+d→K0(Λ)+X reaction in the π+π− (pπ−) decay channel of KS0 (Λ) using a liquid D2 target and internally-tagged photon beams (Eγ=0.80–1.08 GeV) at Research Center for Electron Photon Science (ELPH), Tohoku University. We have renewed the spectrometer (NKS2) and took data with a liquid D2 target in 2005–2007. More recently, we took data in 2010 after a detector upgrade in the vertex region to substantially increase the acceptance. The results of Λ single measurements on a deuterium target were obtained for differential cross-section as a function of momentum, as a function of angle, and integrated cross-section as a function of beam energy. The results are compared with recent theoretical studies: Isobar models (Kaon-MAID and Saclay-Lyon A) and a Regge-plus-Resonance model.
Photoproduction of the
K
0
from the deuteron and the carbon nucleus has been investigated at the Laboratory of Nuclear Science, Tohoku University in Sendai. The Neutral Kaon Spectrometer and the ...Neutral Kaon Spectrometer 2 were developed to detect
π
+
π
−
pairs coming from the decay of the
K
S
0
. The resulting
K
0
momentum spectra for inclusive
K
0
photoproduction were compared with theoretical calculations based on isobar models for
γ
+
n
→
K
0
+
Λ
, utilizing the spectator hypothesis. An upgrade of the inner detectors to enhance the acceptance for the coincidence measurement of the
K
S
0
and Λ is underway. We expect that the exclusive and kinematically complete measurement of the reaction will provide us with direct access to the center-of-mass observables that are important for further understanding the mechanism for strangeness photoproduction.
The photoproduction of the charged pions from the deuteron has been studied with the Neutral Kaon Spectrometer (NKS) and the Neutral Kaon Spectrometer 2 (NKS2) at the Research Center for Electron ...Photon Science, Tohoku University (ELPH) which was previously known as the Laboratory of Nuclear Science (LNS-Tohoku) using the GeV-region tagged photon beam. The total cross section for the quasi-free (QF) π+π− photoproduction from the deuteron was measured with NKS in the energy region from 0.8 to 1.1 GeV. The cross section for the double Δ excitation in the intermediate state was derived in the analysis of the non-quasi-free (NQF) process, in which two nucleons of the deuteron share the energy of the incident photon. The prospect of the measurements of double pion photoproduction with NKS2 and upgraded NKS2 is discussed.
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