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Hypernuclear Project with HRS-HKS at Hall A.
We are also considering an option to perform the experiment at Hall C instead of Hall A.


Physics motivation

  • 3,4ΛH (E12-19-002): ΛN CSB, Hypertriton puzzle
  • 40,48ΛK (E12-15-008): ΛNN interaction, Isospin dependent interaction
  • 208ΛTl (E12-20-013): ΛNN interaction

Experimental equipment

HRS-HKS at Hall A
The experiment is originally planned to be carried out with high resolution spectrometers HRS and HKS
in JLab Hall A for high precision hypernuclear measurement.
Electron beams at 4.24 GeV will be impinged on various targets (3, 4He, 40, 48Ca, 208Pb),
and scattered electrons and K+s from the (e,e'K+) reaction
will be detected by the spectrometers for missing mass spectroscopy of hypernuclei.

HES-HKS at Hall C
There is an option of the usage of HES and HKS at Hall C for the experiment.
However, an optics analysis for the gas target needs at least
one vertical spectrometer by which the production vertex along
the beam direction can be reconstructed with the reasonable resolution.
The spectrometers HES and HKS are both horizontal bending spectrometers,
and need to modify at least one of them to the vertical bending one.








  • K.N. Suzuki (Ph.D. thesis, Kyoto Univ., 2022) → PDF
    "Search for the nnΛ state via the 3H(e,e'K+)X reaction at JLab"


  • B. Pandey (Ph.D. thesis, Hampton Univ., 2021) → web page
    "A Possible Observation of Sigma-nn Continuum Structures and A Bound Sigma-NN State Using the (e,e'K+) Reaction"
  • K. Katayama (Master's thesis, Kyoto Univ., 2021) → PDF
    "Development of HRS-HKS trigger system with FPGA -High precision measurement of hypernuclei at JLab-"
  • T. Toyoda (Master's thesis, Kyoto Univ., 2021) → PDF
    "Basic design of gas target for high accuracy mass measurement of hypertriton at JLab"
  • T. Akiyama (Master's thesis, Tohoku Univ., 2021) → PDF
    "Development of water Cherenkov counter for medium-heavy hypernuclear spectrosocpy at JLab"
  • K. Okuyama (Master's thesis, Tohoku Univ., 2021) → PDF
    "Study of the hyperon electroproduction using the p(e,e'K+)Λ/Σ0 reaction"



  • T. Gogami et al., "Accurate Λ hypernuclear spectroscopy with electromagnetic probe at Jefferson Lab", AIP Conference Proceedings 2319, 080019 (2021) [1]



ELPH workshop C031, ELPH, Nov 4-5, 2021

ELPH workshop E031, ELPH, Sendai, Japan, Nov 4-5, 2021

  • S.N. Nakamura, "Present and future of Λ hypernuclear research at JLab", Nov 4, 2021 (PDF)

Seminar of Nucl. Theory group of Kyoto Univ. (Kyoto Univ., Oct 2021)

  • T. Gogami, "New results and prospects of high precision hypernuclear experiment at JLab", Oct 29, 2021 (PDF)

JPS Meeting (Online, Sep 2021)

  • T. Gogami, "Hypernuclear Physics at Jefferson Laboratory", Sep 17, 2021 (PDF)

WEPH 2021 (Online, Sep 8-9, 2021)

Workshop of Electro- and Photoproduction of Hypernuclei and Related Topics 2021

  • F. Garibaldi, "Studying Λ interactions in nuclear matter with the 208Pb(e,e'K+)208ΛTl reaction", Sep 8, 2021
  • T. Gogami, "Hypertriton and nnΛ measurements at Jefferson Lab" Sep 9, 2021 (PDF)

Hall A/C Collaboration Meeting (Online, Jul 8-9, 2021)

JPS Annual Meeting (Online, 12-15 Mar, 2021)

  • K.N. Suzuki, "Cross section measurement of the 3H(e,e'K+)nnΛ reaction at JLab", Mar 12, 2021 (PDF)
  • K. Okuyama
  • T. Akiyama
  • K. Katayama
  • Y.R. Nakamura

HIN2020 (Online+Kyoto(Japan), 8-10 Mar, 2021)


  • J. Renhold, "The future hypernuclear program at Jefferson Lab", Mar 10, 2021

APFB2020 (Online+Kanazawa(Japan), 1-5 Mar, 2021)


  • K. Katayama, "Trigger system development for the accurate BΛ measurement of Lambda hypertriton at JLab"
  • K. Itabashi, "Study of the nnΛ state and Λn interaction at Jefferson Lab"
  • T. Gogami, "Lambda hypertriton binding energy measurement at Jefferson Lab", Mar 2, 2021 (PDF)

Hall A Winter Collaboration Meeting (Online, Jan 21-22, 2021)

  • B. Pandey, "", Jan 21, 2021
  • T. Gogami, "Future hypernuclear experiments with HKS", Jan 22, 2021 (PDF)