Precise measurement on the binding energy of hypertriton from the nuclear emulsion data using analysis with machine learning


  • Ayumi Kasagi HENP RIKEN, Gifu Univ
  • Enqiang Liu
  • Manami Nakagawa
  • Hiroyuki Ekawa
  • Junya Yoshida
  • Wenbo Dou
  • Abdul Muneem
  • Kazuma Nakazawa
  • Christophe Rappold
  • Nami Saito
  • Takehiko. R. Saito
  • Masato Taki
  • Yoshiki. K. Tanaka
  • He Wang



hypernucleus, hypertriton, binding energy, nuclear emulsion, machine learning


A machine learning model has been developed to search events of production and decay of a hypertriton in nuclear emulsion data, which is used for measuring the binding energy of the hypertriton at the best precision. The developed model employs an established technique for object detection and is trained with surrogate images generated by Monte Carlo simulations and image transfer techniques. The first hypertriton event has already been detected with the developed method only with 10−4 of the total emulsion data. It implies that a sufficient number of hypertriton events will soon be detected for the precise measurement of the hypertriton binding energy.


M. Danysz & J. Pniewski Delayed disintegration of a heavy nuclear fragment I. Phil. Mag. 44, 348-350 (1953). url{}

G. Bohm et al. A determination of the binding-energy values of light hypernuclei. Nucl. Phys. B 4, 511-526 (1968). url{}

M. Juric et al. A new determination of the binding-energy values of the light hypernuclei (A $leqq$ 15). Nucl. Phys. B 52, 1-30 (1973). url{}

O. Hashimoto, H. Tamura Spectroscopy of hypernuclei. Prog. Part. Nucl. Phys. 57 564 (2006). url{}

O. Hashimoto, et al. Hypernuclear Spectroscopy at JLab Hall C. Nucl. Phys. A 835 121 (2010). url{}

C. Rappold et al. J. Phys. Overview of the hypernuclear production in heavy-ion collision experiments Conf. Ser. 668 012025 (2016). url{}

Particle Data Group et al. Review of particle physics. Prog. Theor. Exp. Phys. 2020, 083C01 (2020). {}

C. Rappold et al. Hypernuclear spectroscopy of products from 6Li projectiles on a carbon target at 2 AGeV. Nucl. Phys. A 913, 170-184 (2013). url{}

The STAR Collaboration. Observation of an antimatter hypernucleus. Science 328, 58-62 (2010) url{}

J. Adam et al. $^{3}_{Lambda}rm{H}$ and $Bar{^{3}_{Lambda}rm{H}}$ production in Pb-Pb collisions at $sqrt{sNN} = 2.76$ TeV. Phys. Lett. B 754, 360-372 (2016).

L. Adamczyk et al. Measurement of the $^{3}_{Lambda}rm{H}$ lifetime in Au+Au collisions at the BNL Relativistic Heavy Ion Collider. Phys. Rev. C 97, 054909 (2018). url{}

J. Chen, D. Keane, Y.-G. Ma, A. Tang & Z. Xu.

Antinuclei in heavy-ion collisions. Phys. Rep. 760, 1-39 (2018). url{}

{ALICE_2019} S. Acharya et al. $^{3}_{Lambda}rm{H}$ and $Bar{^{3}_{Lambda}rm{H}}$ lifetime measurement in Pb-Pb collisions at $sqrt{sNN} = 5.02$~TeV via two-body decay. Phys. Lett. B 797, 134905 (2019). url{}

A. Perez-Obiol, D. Gazda, E. Friedman & A. Gal. Revisiting the hypertriton lifetime puzzle. Phys. Lett. B 811, 135916 (2020). url{}

J. Adam et al. Measurement of the mass difference and the binding energy of the hypertriton and antihypertriton. Nat. Phys. 16, 409-412 (2020). url{}

Y-H. Leung Hypernuclei and anti-hypernuclei production in heavy-ion collisions. url{}

Y. Toyama, et al. Status of a Lifetime Measurement of Light Hypernuclei Using High Intensity Tagged Photon Beam at ELPH. Proceedings of the 8th International Conference on Quarks and Nuclear Physics (QNP2018)

(2019). url{DOI 10.7566/jpscp.26.031018}

{nature} T.R Saito New directions in hypernuclear physics. Nature Reviews Physics 2522-5820. (2021). url{10.1038/s42254-021-00371-w}

H. Asano $rm{{^3_{Lambda}H}}$ and $rm{{^4_{Lambda}H}}$ mesonic weak decay lifetime measurement with $rm{^{3,4}He(K^{-},pi^{0})^{3,4}_{Lambda}H}$ reaction. url{}

M. Agnello Direct measurement of the $rm{{^3_{Lambda}H}}$ and $rm{{^4_{Lambda}H}}$ lifetimes using the $rm{^{3,4}He(pi^{-},K^{0})^{3,4}_{Lambda}H}$ reactions. url{}

D. Cebra, Beam Energy Scan II (BES-II) and FXT: Status and Plans url{}

M. FaseUpgrade of the ALICE experiment for LHC Run 3 and beyond url{}

K. Imai, K. Nakazawa, & H. Tamura. J-PARC E07 experiment: Systematic study of double strangeness system with an emulsion-counter hybrid method. Proposal for Nuclear and Particle Physics Experiments at J-PARC. (2006) url{}

M.K. Soe et al. Automatic track following system to study double strangeness nuclei in nuclear emulsion exposed to the observable limit. Nucl. Instrum. Methods Phys. Res. A 848, 66-72 (2017). url{}

H. Ekawa et al. Observation of a Be double-Lambda hypernucleus in the J-PARC E07 experiment. Prog. Theor. Exp. Phys. 2019, 021D02 (2019). url{}

S. H. Hayakawa et al. Observation of coulomb-assisted nuclear bound state of $Xi^-$-$^{14}rm{N}$ system. Phys. Rev. Lett. 126, 062501 (2021). url{}

M. Yoshimoto et al. First observation of a nuclear s-state of a $Xi$ hypernucleus, $rm{{^{15}_{Xi}C}}$. Prog. Theor. Exp. Phys. 2021, 073D02 (2021). url{}

K. Nakazawa et al. The first evidence of a deeply bound state of $rm{Xi}^{-}$ - 14N system. Prog. Theor. Exp. Phys. 2015, 3, 033D02 (2015) url{}

J. Yoshida et al. A new scanning system for alpha decay events as calibration sources for range-energy relation in nuclear emulsion. Nucl. Instrum. Methods Phys. Res. A 847, 86-92 (2017). url{}

Y. LeCun, Y. Bengio & G. Hinton. Deep learning. Nature 521, 436-444 (2015). url{}

K. He, X. Zhang, S. Ren & J. Sun. Deep residual learning for image recognition. Preprint at arXiv (2015). url{}

J. Yoshida et al. CNN-based event classification of alpha-decay events in nuclear emulsion. Nucl. Instrum. Methods Phys. Res. A 989, 164930 (2021). url{}

K. He, G. Gkioxari, P. Dollar, & R. B. Girshick. Mask R-CNN. Preprint at arXiv (2017). url{}

J. Allison Recent developments in Geant4. Nucl. Instrum. Methods Phys. Res. A 835 186-225. (2016) url{}

T. Wang High-resolution image synthesis and semantic manipulation with conditional GANs. Preprint at arXiv url{} (2017).

I. J. Goodfellow et al. Generative adversarial networks. Preprint at arXiv url{} (2014)

W.H. Barkas. Nuclear Research Emulsions. Pure & Applied Physics Series 15-1 (Academic, 1963).

E. Liu Revisiting the former nuclear emulsion data for hypertriton. Eur. Phys. J. A 57, 327 (2021). url{}

A. Esser Observation of $_{mathrm{ensuremath{Lambda}}}^{4}mathrm{H}$ Hyperhydrogen by Decay-Pion Spectroscopy in Electron Scattering. Phys. Rev. Lett 114 232501 (2015) url{}




How to Cite

Kasagi A, Liu E, Nakagawa M, Ekawa H, Yoshida J, Dou W, Muneem A, Nakazawa K, Rappold C, Saito N, Saito T, Taki M, Tanaka Y, Wang H. Precise measurement on the binding energy of hypertriton from the nuclear emulsion data using analysis with machine learning. Supl. Rev. Mex. Fis. [Internet]. 2022 Jun. 1 [cited 2024 May 29];3(3):0308122 1-6. Available from: