High-precision mass measurement of electro-produced Λ hypernuclei at JLab
ORAL
Abstract
Precise mass measurement of Λ hypernuclei, which are nuclei containing a strange quark, are important for understanding ΛN interaction. Our group has successfully performed mass measurement of light Λ hypernuclei via decay pion spectroscopy at Mainz, Germany, as well as medium-mass Λ hypernuclei via (e, e'K+) missing mass spectroscopy at Jefferson Lab (JLab) in the U.S.
We, the JLab Hypernuclear Collaboration, are now planning to extend these spectroscopy techniques and conduct a next-generation experiment on Λ hypernuclei in JLab Hall-C. In this experiment, Λ hypernuclei will be electro-produced by irradiating various targets from 6Li to 208Pb with a 2.2 GeV electron beam. Three high-resolution momentum spectrometers (HKS, HES, ENGE) will be used to simultaneously perform decay pion spectroscopy and (e, e'K+) missing mass spectroscopy, enabling comprehensive and precise measurement of Λ hypernuclear masses across a wide mass range from light to heavy systems.
Through these measurements, we aim to address unresolved problems such as "hyperon puzzle" and "hypertriton puzzle" from multiple perspectives. The proposed experiment has already been approved, and detailed design of the experimental setup and detector preparation are now ongoing toward our beamtime in 2027. In this presentation, we will discuss the overview and physics goals of this hypernuclear experiment at JLab.
We, the JLab Hypernuclear Collaboration, are now planning to extend these spectroscopy techniques and conduct a next-generation experiment on Λ hypernuclei in JLab Hall-C. In this experiment, Λ hypernuclei will be electro-produced by irradiating various targets from 6Li to 208Pb with a 2.2 GeV electron beam. Three high-resolution momentum spectrometers (HKS, HES, ENGE) will be used to simultaneously perform decay pion spectroscopy and (e, e'K+) missing mass spectroscopy, enabling comprehensive and precise measurement of Λ hypernuclear masses across a wide mass range from light to heavy systems.
Through these measurements, we aim to address unresolved problems such as "hyperon puzzle" and "hypertriton puzzle" from multiple perspectives. The proposed experiment has already been approved, and detailed design of the experimental setup and detector preparation are now ongoing toward our beamtime in 2027. In this presentation, we will discuss the overview and physics goals of this hypernuclear experiment at JLab.
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Presenters
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Ken Nishida
- The University of Tokyo