Precise determination of ${}_{\Lambda }^{12}$C level structure by $\gamma$-ray spectroscopy

Abstract

Level structure of the ${}_{\Lambda }^{12}$C hypernucleus was precisely determined by means of $\gamma$-ray spectroscopy. We identified four $\gamma$-ray transitions via the ${}^{12}$C$({\pi }^{+},K^{+}\gamma )$ reaction using a germanium detector array, Hyperball2. The spacing of the ground-state doublet $(2_1^{-},1_1^{-})$ was measured to be $161.5\pm 0.3\text{(stat)}\pm 0.3\text{(syst)}$\,keV from the direct $M1$ transition. Excitation energies of the $1_2^{-}$ and $1_3^{-}$ states were measured to be $2832\pm 3\pm 4$\,keV and $6050\pm 8\pm 7$\,keV, respectively. The obtained level energies provide definitive references for the reaction spectroscopy of $\Lambda$ hypernuclei.

References in corpus (2)

• High Resolution Spectroscopy of 12B_Lambda by Electroproduction
• The experiments with the High Resolution Kaon Spectrometer at JLab Hall C and the new spectroscopy of ${}_{\Lambda }^{12}\text{B}$ hypernuclei

Cited by in corpus (9)

• Strangeness in nuclear physics
• Hadron Physics at J-PARC
• High-resolution hypernuclear spectroscopy at Jefferson Lab, Hall A
• Low-lying level structure of $\Lambda$ hypernuclei and spin dependence of $\Lambda N$ interaction with antisymmetrized molecular dynamics
• Excitation energy shift and size difference of low-energy levels in $p$-shell $\Lambda$ hypernuclei
• Spectroscopy of $A=9$ hyperlithium by the $(e,e^{\prime }{K}^{+})$ reaction
• Experimental techniques and performance of $\Lambda$-hypernuclear spectroscopy with the $(e,e^{\prime }{K}^{+})$ reaction
• Structures of $p$-shell double-$\Lambda$ hypernuclei studied with microscopic cluster models
• $p$-shell hypernuclear structures using the Gogny-interaction shell model