Photo-production of neutral kaons on 12C in the threshold region

Abstract

Kaon photo-production process on $^{12}$C has been studied by measuring neutral kaons in a photon energy range of 0.8$-$1.1 GeV. Neutral kaons were identified by the invariant mass constructed from two charged pions emitted in the $K^{0}_{S}\to\pi^{+}\pi^{-}$ decay channel. The differential cross sections as well as the integrated ones in the threshold photon energy region were obtained. The obtained momentum spectra were compared with a Spectator model calculation using elementary amplitudes of kaon photo-production given by recent isobar models. Present result provides, for the first time, the information on $n(\gamma,K^{0})\Lambda$ reaction which is expected to play an important role to construct models for strangeness production by the electromagnetic interaction. Experimental results show that cross section of $^{12}{\rm C}(\gamma,K^0)$ is of the same order to that of $^{12}{\rm C}(\gamma,K^+)$ and suggest that slightly backward $K^0$ angular distribution is favored in the $\gamma n\to K^0\Lambda$ process.Comment: 6 pages, 8 figure

Contribution of higher nucleon resonances toK*Λphotoproduction

“…This was shown manifestly in the investigation of kaon photoproduction off the nucleon targets, i.e., γN → KΛ(1116), which has been studied intensively both theoretically and experimentally [1][2][3][4][5][6][7][8][9]. These works show that nucleon resonances play a crucial role in understanding the production mechanisms of the reaction in the resonance region [6,7].…”

The Recent Results of Strangeness Photoproduction in the Threshold Region at ELPH-Tohoku

“…After the successful measurement of inclusive K 0 photoproduction cross sections on the neutron with the Neutral Kaon Spectrometer (NKS) [7,8], we developed the Neutral Kaon Spectrometer 2 (NKS2) mainly for detection of Λ with improved acceptance in the forward angular region. We performed the inclusive measurements of K 0 and Λ using invariant masses of π + π − for K 0 identification and pπ − for Λ identification.…”

K0Λ Photoproduction Studied with an Electromagnetic Calorimeter FOREST

“…The γn → K 0 Λ reaction is expected to be an easy channel for extracting N * information due to the absence of charged particle exchange terms. Experimental studies of K 0 Λ photoproduction were performed by Watanabe et al [5] and Tsukada et al [6]. Both their experiments (the NKS collaboration) were conducted using carbon and liquid deuterium targets, respectively, at the Laboratory of Nuclear Science (LNS), which is now called the Research Center for Electron Photon Science (ELPH).…”