Unique approach for precise determination of binding energies of hypernuclei with nuclear emulsion and machine learning

4 pags., 1 tab. -- HYP2022 - 14th International Conference on Hypernuclear and Strange Particle PhysicsHypertriton is the lightest hypernucleus and a benchmark in hypernuclear physics. However, it has recently been suggested that its lifetime and binding energy values may differ from the established values. To solve this puzzle, it is necessary to measure both values with a higher precision. For the precise measurement of the binding energy, we are aiming at developing a novel technique to measure the hypertriton binding energy with unprecedented accuracy by combining nuclear emulsion data and machine learning techniques. The analysis will be based on the J-PARC E07 nuclear emulsion data. Furthermore, a machine-learning model is being developed to identify other single and double-strangeness hypernucle

A compact start time counter using plastic scintillators readout with MPPC arrays for the WASA-FRS HypHI experiment

9 pags., 12 figs.We have developed a compact detector for measuring beam particles using plastic scintillators readout through Multi-Pixel Photon Counters, which is employed for hypernuclear measurements in the WASA-FRS experiment at GSI. The Time-of-Flight resolution of the newly-developed detector has been investigated in relation to the overvoltage with respect to the breakdown voltage, a maximum counting rate of approximately 3×106/s per segment, and a maximum beam charge of Z = 6. The evaluated Time-of-Flight resolutions between the neighboring segments of the detector range from 44.6±1.3 ps to 100.3±3.6 ps (σ) depending on the segment, overvoltage values, and beam intensity. It is also observed that the Time-of-Flight resolution is inversely correlated to the beam atomic charge (Z).The WASA-FRS project is supported by the JSPS KAKENHI, Japan (Grant Numbers JP18H01242), the JSPS Grant-in-Aid for Early-Career Scientists (Grant No. JP20K14499), the JSPS Fostering Joint International Research (B) (Grant No. JP20KK0070), Proyectos I+D+i 2020 ref: PID2020-118009GA-I00 ; grant 2019- T1/TIC-13194 of the program Atracción de Talento Investigador of the Community of Madrid, the Regional Government of Galicia under the Postdoctoral Fellowship Grant No. ED481D-2021-018, the ‘‘Ramón y Cajal’’ program under the Grant No. RYC2021-031989-I, the SciMat and qLife Priority Research Areas budget under the program Excellence Initiative - Research University at the Jagiellonian University and the European Unions Horizon 2020 research and innovation programme under grant agreement No 824093. The project is also supported by the JustusLiebig-Universität (JLU), Gießen, Germany, and GSI, Germany under the JLU-GSI strategic Helmholtz partnership agreement. This research is supported in part by the ExtreMe Matter Institute EMMI at the GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt, Germany.Peer reviewe

Studies of hypernuclei with heavy-ion beams, nuclear emulsions and machine learning - T. R. Saito, for the WASA-FRS collaboration and the Emulsion-ML collaboration

Presentación con 75 diapositivas, HYP2022, June 27th – July 1st, Prague, 2022The lightest hypernucleus, the hypertriton, has been a benchmark in the field of hypernuclear physics. However, some of recent experiments employing energetic heavy-ion beams have revealed that the hypertriton lifetime is significantly shorter than 263 ps which is expected by considering the known weakly binding nature of the hypertriton. The STAR collaboration has also measured the hypertriton binding energy, and the deduced value is contradicting to its formerly known small binding energy. These measurements have indicated that the fundamental physics quantities of the hypertriton such as its lifetime and binding energy have not been understood, therefore, they have to be measured very precisely. Furthermore, an unprecedented Λnn bound state observed by the HypHI collaboration has to be studied in order to draw a conclusion whether or not such a bound state exists. These three-body hypernuclear states are studied by the heavy-ion beam data in the WASA-FRS experiment and by analysing J-PARC E07 nuclear emulsion data with machine learnin

Study of hypernuclei in the reaction 6Li+ I2C at 2 A Oe V

Cette thèse présente une nouvelle approche expérimentale proposée par la collaboration HypHI pour l’étude des hypernoyaux dans des réactions induites par des faisceaux d’ions lourds stables ou radioactifs. La méthode proposée permet de mesurer les hypernoyaux formés par coalescence entre un hypéron Λ produit dans la région des participants et un fragment spectateur issu du projectile. Ce mode de production offre la possibilité d’étudier les hypernoyaux dans des conditions extrêmes d’isospin et de mesurer directement leur moment magnétique hypernucléaire. Une première expérience ayant pour objectif principal de démontrer la faisabilité de la nouvelle méthode proposée, a été réalisée en effectuant une spectroscopie précise des hypernoyaux 4 ΛH, 3 ΛH et 5 ΛHe produits dans les collisions 6Li+12C à une énergie incidente de 2 GeV par nucléon. La conception, le développement et la réalisation du nouveau dispositif de détection sont présentés. Les performances des détecteurs, ainsi que celles du système de déclenchement ont été étudiées. Le code d’analyse développé pour la reconstruction des hypernoyaux est présenté ainsi que ses performances sur les données simulées. L’analyse des données expérimentales et les premiers résultats de la reconstruction de l’hypéron Λ et de l’hypernoyau 5 ΛHe, ainsi que la mesure de leur temps de vie, sont présentés. Ces premiers résultats démontrent la faisabilité de cette nouvelle approche expérimentale pour l’étude des hypernoyaux et ouvrent de nouvelles perspectives dans la recherche d’hypernoyaux lourds et proches des limites de stabilité.This thesis presents a new experimental approach proposed by the HypHI collaboration to study hypernulei by means of reactions induced by stable and radioactive heavy-ion beams. The proposed method allows to measure hypernuclei formed by coalescence of a Λ-hyperon produced in the participant region and a projectile spectator fragment. Such a production mode offers the opportunity to investigate hypernuclei at extreme isospin and to measure directly hypernuclear magnetic moments. A first experiment aiming at demonstrating the feasibility of this new method has been carried out with a 6Li beam at 2 A GeV impinged on a 12C target by identifying 3 ΛH, 4 ΛH and 5 ΛHe hypernuclei from their mesonic weak decay modes. The design, development and realization of this experiment are presented. Performances of the detectors and of the trigger system have been investigated. The software analysis developed for the reconstruction of hypernuclei is presented and its performances are evaluated using simulated data. The data analysis and preliminary results of the reconstruction of Λ hyperons and of 5 ΛHe and the measurement of their lifetime are reported. The results demonstrate the feasibility of the new experimental approach for the study of hypernuclei and open new perspectives to investigate heavier hypernuclei toward the proton and neutron drip lines

Étude des hypernoyaux dans la réaction 6Li+12C à 2 GeV/nucléon

Cette thèse présente une nouvelle approche expérimentale proposée par la collaboration HypHI pour l'étude des hypernoyaux dans des réactions induites par des faisceaux d'ions lourds stables ou radioactifs. La méthode proposée permet de mesurer les hypernoThis thesis presents a new experimental approach proposed by the HypHI collaboration to study hypernulei by means of reactions induced by stable and radioactive heavy-ion beams. The proposed method allows to measure hypernuclei formed by coalescence of

Étude des hypernoyaux dans la réaction 6Li+12C à 2 GeV/nucléon

Cette thèse présente une nouvelle approche expérimentale proposée par la collaboration HypHI pour l'étude des hypernoyaux dans des réactions induites par des faisceaux d'ions lourds stables ou radioactifs. La méthode proposée permet de mesurer les hypernoyaux formés par coalescence entre un hypéron produit dans la région des participants et un fragment spectateur issu du projectile. Ce mode de production offr la possibilité d'étudier les hypernoyaux dans des conditions extrêmes d'isospin et de mesurer directement leur moment magnétique hypernucléaire. Une première expérience ayant pour objectif principal de démontrer la faisabilité de la nouvelle méthode proposée, a été réalisée en effectuant une spectroscopie précise des hypernoyaux 4 H, 3 H et 5 He produits dans les collisions 6Li+12C à une énergie incidente de 2 GeV par nucléon. La conception, le développement et la réalisation du nouveau dispositif de détection sont présentés. Les performances des détecteurs, ainsi que celles du système de déclenchement ont été étudiées. Le code d'analyse développé pour la reconstruction des hypernoyaux est présenté ainsi que ses performances sur les données simulées. L'analyse des données expérimentales et les premiers résultats de la reconstruction de l'hypéron et de l'hypernoyau 5 He, ainsi que la mesure de leur temps de vie, sont présentés. Ces premiers résultats démontrent la faisabilité de cette nouvelle approche expérimentale pour l'étude des hypernoyaux et ouvrent de nouvelles perspectives dans la recherche d'hypernoyaux lourds et proches des limites de stabilité.This thesis presents a new experimental approach proposed by the HypHI collaboration to study hypernulei by means of reactions induced by stable and radioactive heavy-ion beams. The proposed method allows to measure hypernuclei formed by coalescence of a -hyperon produced in the participant region and a projectile spectator fragment. Such a production mode offers the opportunity to investigate hypernuclei at extreme isospin and to measure directly hypernuclear magnetic moments. A first experiment aiming at demonstrating the feasibility of this new method has been carried out with a 6Li beam at 2 A GeV impinged on a 12C target by identifying 3 H, 4 H and 5 He hypernuclei from their mesonic weak decay modes. The design, development and realization of this experiment are presented. Performances of the detectors and of the trigger system have been investigated. The software analysis developed for the reconstruction of hypernuclei is presented and its performances are evaluated using simulated data. The data analysis and preliminary results of the reconstruction of hyperons and of 5 He and the measurement of their lifetime are reported. The results demonstrate the feasibility of the new experimental approach for the study of hypernuclei and open new perspectives to investigate heavier hypernuclei toward the proton and neutron drip lines

WASA-FRS HypHI experiment at GSI for studying light hypernuclei - Hiroyuki Ekawaa for WASA-FRS Collaboration

Presentación con 17 dispositivas. -- 5 pags. 4 figs., 2 tabs. -- HYP2022 - 14th International Conference on Hypernuclear and Strange Particle Physics. From January till March 2022, the WASA-FRS HypHI experiment performed a precise measurement of the hypertriton and the 4 ΛH hypernucleus lifetime at GSI. The data collected should also confirm whether or not the nnΛ bound state can exist. The experiment were carried out with the WASA central detector with a complex of additional dedicated detectors mounted together at the mid-focal plane of the high-momentum-resolution forward spectrometer, the so-called fragment separator FRS. Hypernuclei of interest were produced by induced reactions of 6Li projectiles at 1.96 A GeV on a diamond target with a thickness of 9.87 g/cm2 . Negatively charged π mesons from two-body decays of the hypernuclei of interest were measured by the WASA and the other detectors, and the residual nuclei after the π − decay were measured by the FRS with a momentum resolving power of 104

Étude des hypernoyaux dans la réaction 6Li+12C à 2 GeV/nucléon

Cette thèse présente une nouvelle approche expérimentale proposée par la collaboration HypHI pour l étude des hypernoyaux dans des réactions induites par des faisceaux d ions lourds stables ou radioactifs. La méthode proposée permet de mesurer les hypernoyaux formés par coalescence entre un hypéron produit dans la région des participants et un fragment spectateur issu du projectile. Ce mode de production offre la possibilité d étudier les hypernoyaux dans des conditions extrêmes d isospin et de mesurer directement leur moment magnétique hypernucléaire. Une première expérience ayant pour objectif principal de démontrer la faisabilité de la nouvelle méthode proposée, a été réalisée en effectuant une spectroscopie précise des hypernoyaux 4 H, 3 H et 5 He produits dans les collisions 6Li+12C à une énergie incidente de 2 GeV par nucléon. La conception, le développement et la réalisation du nouveau dispositif de détection sont présentés. Les performances des détecteurs, ainsi que celles du système de déclenchement ont été étudiées. Le code d analyse développé pour la reconstruction des hypernoyaux est présenté ainsi que ses performances sur les données simulées. L analyse des données expérimentales et les premiers résultats de la reconstruction de l hypéron et de l hypernoyau 5 He, ainsi que la mesure de leur temps de vie, sont présentés. Ces premiers résultats démontrent la faisabilité de cette nouvelle approche expérimentale pour l étude des hypernoyaux et ouvrent de nouvelles perspectives dans la recherche d hypernoyaux lourds et proches des limites de stabilité.This thesis presents a new experimental approach proposed by the HypHI collaboration to study hypernulei by means of reactions induced by stable and radioactive heavy-ion beams. The proposed method allows to measure hypernuclei formed by coalescence of a -hyperon produced in the participant region and a projectile spectator fragment. Such a production mode offers the opportunity to investigate hypernuclei at extreme isospin and to measure directly hypernuclear magnetic moments. A first experiment aiming at demonstrating the feasibility of this new method has been carried out with a 6Li beam at 2 A GeV impinged on a 12C target by identifying 3 H, 4 H and 5 He hypernuclei from their mesonic weak decay modes. The design, development and realization of this experiment are presented. Performances of the detectors and of the trigger system have been investigated. The software analysis developed for the reconstruction of hypernuclei is presented and its performances are evaluated using simulated data. The data analysis and preliminary results of the reconstruction of hyperons and of 5 He and the measurement of their lifetime are reported. The results demonstrate the feasibility of the new experimental approach for the study of hypernuclei and open new perspectives to investigate heavier hypernuclei toward the proton and neutron drip lines.STRASBOURG-Sc. et Techniques (674822102) / SudocSTRASBOURG-Bib.Central Recherche (674822133) / SudocSudocFranceF

Unique approach for precise determination of binding energies of hypernuclei with nuclear emulsion and machine learning

Hypertriton is the lightest hypernucleus and a benchmark in hypernuclear physics. However, it has recently been suggested that its lifetime and binding energy values may differ from the established values. To solve this puzzle, it is necessary to measure both values with a higher precision. For the precise measurement of the binding energy, we are aiming at developing a novel technique to measure the hypertriton binding energy with unprecedented accuracy by combining nuclear emulsion data and machine learning techniques. The analysis will be based on the J-PARC E07 nuclear emulsion data. Furthermore, a machine-learning model is being developed to identify other single and double-strangeness hypernuclei

New directions in hypernuclear physics

11 pags. 3 figs., 1 tab.A hypernucleus, a subatomic bound system with at least one hyperon, is a great test ground to investigate nuclear forces and general baryonic interactions with up, down and strange quarks. Hypernuclei have been extensively studied for almost seven decades in reactions involving cosmic rays and with accelerator beams. In recent years, experimental studies of hypernuclei have entered a new stage using energetic collisions of heavy-ion beams. However, these investigations have revealed two puzzling results related to the lightest three-body hypernuclear system, the so-called hypertriton, and the unexpected existence of a bound state of two neutrons with a Λ hyperon. Solving these puzzles will not only impact our understanding of the fundamental baryonic interactions with strange quarks but also of the nature of the deep interior of neutron stars. In this Perspective, we discuss approaches to solving these puzzles, including experiments with heavy-ion beams and the analysis of nuclear emulsions using state-of-the-art technologies. We summarize ongoing projects and experiments at various facilities worldwide and outline future perspectives.Discussions presented for the WASA-FRS experiment here are based on the experiment S447, which is currently scheduled in 2022 at the FRS at the GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany) in the context of FAIR Phase-0. The authors thank the accelerator departments at GSI and IMP, the FRS department at GSI and the Experiment Electronics department at GSI for the technical support. The authors thank the J-PARC E07 collaboration to provide us the nuclear emulsion data. The authors thank Luise Doersching-Steitz of GSI, Rita Krause of GSI, Yukiko Kurakata of RIKEN, Daniela Press of GSI, Miao Yang of IMP and Xiaohua Yuan of IMP for supporting the projects, including the administrative works. The authors also thank Risa Kobayashi of RIKEN and Yoko Tsuchii of Gifu University for their technical support in mining hypertriton events in the E07 nuclear emulsions. KN, JY, and MY acknowledge support by JSPS KAKENHI Grant Numbers JP23224006, JP16H02180, JP20H00155, and JP20J00682, and MEXT KAKENHI Grant Numbers JP24105002 (Grant-in-Aid for Scientific Research on Innovative Areas 2404), JP18H05403, and JP19H05147 (Grant-in-Aid for Scientific Research on Innovative Areas 6005). SE and CR are supported by the grant 2019-T1/TIC-13194 of the program "Atracción de Talento Investigador" of the Community of Madrid