In-gas-cell laser spectroscopy of the magnetic dipole moment of the N≈126 isotope Pt199

The magnetic dipole moment and mean-square charge radius of 199gPt (Iπ= 5/2−,t1/2=30.8 min) ground state and 199mPt (Eex=424 keV, Iπ= (13/2)+,t1/2=13.6 s) isomeric state are evaluated for the first time from investigations of the hyperfine splitting of the λ1=248.792 nm transition by in-gas-cell laser ionization spectroscopy. Ground and isomeric states of neutron-rich 199Pt nucleus were produced by a multinucleon transfer reaction at the KEK Isotope Separation System (KISS), designed for the study of nuclear spectroscopy in the vicinity of N=126. The measured magnetic dipole moments +0.75(8)μN and −0.57(5)μN are consistent with the systematics of those of nuclei with Iπ= 5/2− and Iπ= 13/2+, respectively

Gamma-Ray Spectroscopy in Lambda Hypernuclei

The present status of hypernuclear gamma-ray spectroscopy with Hyperball is summarized. We observed two gamma transitions of 16-Lambda-O(1- -> 1-,0-) and obtained the strength of the Lambda-N tensor force. In 10B(K-,pi- gamma) data, we did not observe the spin-flip M1 transition of 10-Lambda-B(2- -> 1-), but gamma rays from hyperfragments such as 7-Lambda-Li(7/2+ -> 5/2+) and 9-Lambda-Be(3/2+ ->1/2+) were observed. In 11B(pi+,K+ gamma) data, we observed six gamma transitions of 11_Lambda-B. We also attempted an inclusive gamma-ray measurement with stopped K- beam.Comment: 10 pages, 9 figures, 8th International Conference on Hypernuclear and Strange Particle Physics (HYP2003), Newport News, Virginia, 14-18 Oct 2003, to appear in Nuclear Physics

Beam and SKS spectrometers at the K1.8 beam line

High-resolution spectrometers for both incident beams and scattered particles have been constructed at the K1.8 beam line of the Hadron Experimental Facility at J-PARC. A point-to-point optics is realized between the entrance and exit of QQDQQ magnets for the beam spectrometer. Fine-pitch wire chamber trackers and hodoscope counters are installed in the beam spectrometer to accept a high rate beam up to 107 Hz. The superconducting kaon spectrometer for scattered particles was transferred from KEK with modifications to the cryogenic system and detectors. A missing-mass resolution of 1.9 ± 0.1 MeV/c2 (FWHM) was achieved for the ∑ peaks of (π±, K+) reactions on a proton target in the first physics run of E19 in 2010

In-gas-cell laser resonance ionization spectroscopy of Ir 196,197,198

Hyperfine structure (HFS) measurements of neutron-rich iridium isotopes Ir196,197,198 (Z=77,N=119-121) were performed via in-gas-cell laser resonance ionization spectroscopy at the KEK Isotope Separation System. Magnetic dipole moments μ and isotope shifts were determined from the HFS spectra. The variation of mean-square charge radii and quadrupole deformation parameters of these isotopes were evaluated from the isotope shifts. The μ value of Ir197 agreed with a theoretical value based on the strong coupling model, and the Ir nucleus was interpreted as prolately deformed by the theoretical calculations. The μ values of Ir196,198 were also compared with semiempirical values calculated based on the strong coupling model. From the comparison, we can suggest the possible spin values of Iπ=1,2- for Ir196 and Iπ=1- for Ir198

γ -ray spectroscopy study of

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 +)12 ΛC reaction was employed to populate 12 ΛC/11 ΛB 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