DATE2026.04.17 #Press Releases
World’s Highest-Precision Measurement of the Hypertriton
Disclaimer: machine translated by DeepL which may contain errors.
World’s Highest-Precision Measurement of the Hypertriton
The hypertriton newly measured by decay pion spectroscopy
Summary
Assistant Professor Sho Nagao at the Graduate School of Science, The University of Tokyo (also a visiting scientist at RIKEN), Professor Satoshi N. Nakamura at the Graduate School of Science, The University of Tokyo(also a visiting scientist at RIKEN and Professor of Tohoku University), Special Postdoctoral Researcher Ryoko Kino of the RIKEN Nishina Center for Accelerator-Based Science (who was a graduate student at Tohoku University at the time of the research), Professor Josef Pochodzalla, and Professor Patrick Achenbach of Johannes Gutenberg University Mainz have performed decay pion spectroscopy of Lambda hypernuclei (hereinafter referred to as hypernuclei) at the Mainz Microtron (MAMI). They measured the Lambda binding energy of the hypertriton with the world’s highest precision.
Hypernuclei are short-lived nuclei that contain one or more hyperons in addition to protons and neutrons. They provide important clues for exploring the nature and origin of the strong force that shapes atomic nuclei. In particular, the hypertriton, the lightest hypernucleus, serves as an important benchmark for testing theoretical calculations of few-body systems.
In this study, the research group achieved high-precision energy calibration by simultaneously measuring decay pions from hyperhydrogen-4 and using its known Lambda binding energy as a reference. The results suggest that the hypertriton is more strongly bound than previously thought. This achievement is expected to contribute to a better understanding of hyperon–nucleon interactions, the structure of light hypernuclei, and the properties of matter inside neutron stars, which are extremely dense astrophysical objects.
Links
Tohoku University, RIKEN, Johannes Gutenberg University of Mainz
Publication Information
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Journal name Physical Review Letters Title of paper Precise measurement of the Λ-binding energy difference between 3ΛH and 4ΛH via decay-pion spectroscopy at MAMIAuthors Ryoko Kino, Sho Nagao, Patrick Achenbach, Satoshi N. Nakamura, Josef Pochodzalla, et al. DOI 10.1103/19gd-jqw2