In the above-named study of the neutral kaon photoproduction, the cross sections given in Figs. 10 and 11 were wrong due to trivial mistakes, mainly in estimating the number of beam photons. The normalization factors for the cross sections are found to be larger by a factor of approximately 3.9 compared to the previous one, though it depends on the K 0 momentum. The corrected spectra are shown in Fig. 11 (numberings are the same as the original ones). As a result, the r K 1 Kγ value obtained by fitting the K 0 spectra in the lower photon energy region (0.9 E γ < 1.0 GeV) should be replaced by the new value of r K 1 Kγ = −1.405 for the Saclay-Lyon A (SLA) model. The phenomenological parameters are also changed: a 0 = 0.3532, a 1 = −0.2152, a 2 = −0.0359, and e 0 = −0.0866 with χ 2 /n.d.f. = 0.80.By these corrections, the experimental cross sections are larger than those calculated by the Kaon-MAID model in the momentum region of P K 0 < 0.4 GeV/c both in the lower and higher photon beam energies. However, the K 0 spectral shapes in the laboratory system are essentially the same as those of the previous ones and the discussion does not change. In Fig. 12, the K 0 angular distributions for the SLA and PH models calculated with the new parameters are shown together with those for the Kaon-MAID model. It suggests a much enhanced backward K 0 distribution in the c.m. system because the SLA and PH1 models are preferred to reproduce the new results with larger cross sections.

The photoproduction process of neutral kaons on a liquid deuterium target is investigated near the threshold region, Eγ = 0.8-1.1 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(γ, K 0 )Λ process, which provides additional constraints on current models of kaon photoproduction. The present study demonstrates that the n(γ, K 0 )Λ reaction can provide key information on the mechanism of the photoproduction of strangeness.

Muons have been accelerated by using a radio frequency accelerator for the first time. Negative muonium atoms (Mu − ), which are bound states of positive muons (µ + ) and two electrons, are generated from µ + 's through the electron capture process in an aluminum degrader. The generated Mu − 's are initially electrostatically accelerated and injected into a radio frequency quadrupole linac (RFQ). In the RFQ, the Mu − 's are accelerated to 89 keV. The accelerated Mu − 's are identified by momentum measurement and time of flight. This compact muon linac opens the door to various muon accelerator applications including particle physics measurements and the construction of a transmission muon microscope.

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A buncher cavity has been developed for the muons accelerated by a radio-frequency quadrupole linac (RFQ). The buncher cavity is designed for β = v/c = 0.04 at an operational frequency of 324 MHz. It employs a double-gap structure operated in the TEM mode for the required effective voltage with compact dimensions, in order to account for the limited space of the experiment. The measured resonant frequency and unloaded quality factor are 323.95 MHz and 3.06 × 10 3 , respectively. The buncher cavity was successfully operated for longitudinal bunch size measurement of the muons accelerated by the RFQ.