N. Terada

γ-ray spectroscopy study of 11ΛB and 12ΛC

In this paper, a preliminary result from the latest hypernuclear γ-ray spectroscopy experiment (KEK-E566) is presented together with a short discussion. The experiment was performed at the KEK-PS K6 beam line in 2005. In this experiment, the 12C(π +,K +) Λ 12 C reaction was employed to populate Λ 12 C/ Λ 11 B hypernuclei. A germanium detector array, Hyperball2, was constructed to detect γ-rays emitted from the hypernuclei produced. Three hypernuclear γ-ray peaks were observed and assigned.

Neutral Kaon Photo‐Production in the Threshold Energy Region

We have been conducting an experimental program to study strangeness photoproduc‐tions on the deuteron by measuring K0 and Λ in the threshold energy region. The π−π+ from K0 and π−p from Λ are detected by use of large acceptance magnetic spectrometers. At the first stage of the program, we started with Neutral Kaon Spectrometer (NKS), which consisted of timing counters and tracking devices in the magnetic field. The NKS spectrometer was employed to measure K0 photoproductions from deuteron and carbon target for the first time. A newly constructed spectrometer (NKS2) has been employed for the second stage experiment. It consists of a 110 ton dipole magnet and a combination of detectors. The momentum distributions of K0 and A from γ+d process were observed, and compared with the calculations based on the isobar models. The NKS2 spectrometer has been upgraded by installing a three dimensional tracking device in the central region. This improvement enables to explore the simultaneous measurement of the K0‐A w...

NEUTRAL KAON PHOTOPRODUCTION AT LNS, TOHOKU UNIVERSITY

The elementary photo-strangeness production process has been intensively studied based on the high-quality data of the charged kaon channel, γ + p → K+ + Λ(Σ0). However, there had been no reliable data for the neutral kaon channel γ + n → K0 + Λ(Σ0) and the theoretical investigations suffer seriously from the lack of the data. In order to have reliable data for the neutral kaon photo-production data, substantial effort has been made to measure the γ + n → K0 + Λ process in the π+π- decay channel, using a liquid deuterium target and a tagged photon beam (Eγ = 0.8-1.1 GeV) in the threshold region at the Laboratory of Nuclear Science (LNS), Tohoku University. We have taken exploratory data quite successfully with the use of Neutral Kaon Spectrometer (NKS) at LNS-Tohoku in 2003 and 2004. The data is compared to theoretical models and it indicates a hint that the K0 differential cross section has a backward peak in the energy region. The second generation of the experiment, NKS2, is designed to extend the NKS experiment by considerably upgrading the original neutral kaon spectrometer, fully replacing the spectrometer magnet, tracking detectors and all the trigger counters. The new spectrometer NKS2 has significantly larger acceptance for neutral kaons compared with NKS, particularly covering forward angles and much better invariant mass resolution. The estimated acceptance of NKS2 is three (ten) times larger for than that of NKS. The spectrometer is newly constructed and installed at the Laboratory of Nuclear Science, Tohoku University in 2005. The deuterium target data was taken with tagged photon beam in 2006-2007. We will report recent results of NKS2 in this paper. Additionally, a status of the upgrade project that gives us larger acceptance and capability of K0 + Λ coincidence measurement will be presented.

Precise determination of Λ12C level structure by γ-ray spectroscopy

Level structure of the

Precise determination of Λ12C level structure byγ-ray spectroscopy

^{12}_{\Lambda}

Updated results on the 11ΛB and 12ΛC γ-ray spectroscopy study

C hypernucleus was precisely determined by means of

Kaon photoproduction on the deuteron at Sendai

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γ -ray spectroscopy study of 11 ΛB and 12 ΛC

-ray spectroscopy. We identified four

Gamma-ray spectroscopy of 12ΛC via the (π+,K+) reaction

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The investigation of strangeness photoproduction in the threshold region at ELPH-Tohoku

-ray transitions via the