18 research outputs found
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
Study of hypernuclei in the reaction 6Li+ I2C at 2 A Oe V
Cette thĂšse prĂ©sente une nouvelle approche expĂ©rimentale proposĂ©e par la collaboration HypHI pour lâĂ©tude des hypernoyaux dans des rĂ©actions induites par des faisceaux dâions lourds stables ou radioactifs. La mĂ©thode proposĂ©e permet de mesurer les hypernoyaux formĂ©s par coalescence entre un hypĂ©ron Î produit dans la rĂ©gion des participants et un fragment spectateur issu du projectile. Ce mode de production offre la possibilitĂ© dâĂ©tudier les hypernoyaux dans des conditions extrĂȘmes dâisospin et de mesurer directement leur moment magnĂ©tique hypernuclĂ©aire. Une premiĂšre expĂ©rience ayant pour objectif principal de dĂ©montrer la faisabilitĂ© de la nouvelle mĂ©thode proposĂ©e, a Ă©tĂ© rĂ©alisĂ©e en effectuant une spectroscopie prĂ©cise des hypernoyaux 4 ÎH, 3 ÎH et 5 ÎHe produits dans les collisions 6Li+12C Ă une Ă©nergie incidente de 2 GeV par nuclĂ©on. La conception, le dĂ©veloppement et la rĂ©alisation du nouveau dispositif de dĂ©tection sont prĂ©sentĂ©s. Les performances des dĂ©tecteurs, ainsi que celles du systĂšme de dĂ©clenchement ont Ă©tĂ© Ă©tudiĂ©es.
Le code dâanalyse dĂ©veloppĂ© pour la reconstruction des hypernoyaux est prĂ©sentĂ© ainsi que ses performances sur les donnĂ©es simulĂ©es. Lâanalyse des donnĂ©es expĂ©rimentales et
les premiers rĂ©sultats de la reconstruction de lâhypĂ©ron Î et de lâhypernoyau 5 ÎHe, ainsi que la mesure de leur temps de vie, sont prĂ©sentĂ©s. Ces premiers rĂ©sultats dĂ©montrent
la faisabilitĂ© de cette nouvelle approche expĂ©rimentale pour lâĂ©tude des hypernoyaux et ouvrent de nouvelles perspectives dans la recherche dâhypernoyaux lourds et proches des limites de stabilitĂ©.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 Î-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 ÎH, 4 ÎH and 5 ÎHe 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 Î hyperons and of 5 ÎHe 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
Ătude des hypernoyaux dans la rĂ©action 6Li+12C Ă 2 GeV/nuclĂ©on
Cette thÚse 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
Ătude des hypernoyaux dans la rĂ©action 6Li+12C Ă 2 GeV/nuclĂ©on
Cette thĂšse prĂ©sente une nouvelle approche expĂ©rimentale proposĂ©e par la collaboration HypHI pour l'Ă©tude des hypernoyaux dans des rĂ©actions induites par des faisceaux d'ions lourds stables ou radioactifs. La mĂ©thode proposĂ©e permet de mesurer les hypernoyaux formĂ©s par coalescence entre un hypĂ©ron produit dans la rĂ©gion des participants et un fragment spectateur issu du projectile. Ce mode de production offr la possibilitĂ© d'Ă©tudier les hypernoyaux dans des conditions extrĂȘmes d'isospin et de mesurer directement leur moment magnĂ©tique hypernuclĂ©aire. Une premiĂšre expĂ©rience ayant pour objectif principal de dĂ©montrer la faisabilitĂ© de la nouvelle mĂ©thode proposĂ©e, a Ă©tĂ© rĂ©alisĂ©e en effectuant une spectroscopie prĂ©cise des hypernoyaux 4 H, 3 H et 5 He produits dans les collisions 6Li+12C Ă une Ă©nergie incidente de 2 GeV par nuclĂ©on. La conception, le dĂ©veloppement et la rĂ©alisation du nouveau dispositif de dĂ©tection sont prĂ©sentĂ©s. Les performances des dĂ©tecteurs, ainsi que celles du systĂšme de dĂ©clenchement ont Ă©tĂ© Ă©tudiĂ©es. Le code d'analyse dĂ©veloppĂ© pour la reconstruction des hypernoyaux est prĂ©sentĂ© ainsi que ses performances sur les donnĂ©es simulĂ©es. L'analyse des donnĂ©es expĂ©rimentales et les premiers rĂ©sultats de la reconstruction de l'hypĂ©ron et de l'hypernoyau 5 He, ainsi que la mesure de leur temps de vie, sont prĂ©sentĂ©s. Ces premiers rĂ©sultats dĂ©montrent la faisabilitĂ© de cette nouvelle approche expĂ©rimentale pour l'Ă©tude des hypernoyaux et ouvrent de nouvelles perspectives dans la recherche d'hypernoyaux lourds et proches des limites de stabilitĂ©.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
Ătude des hypernoyaux dans la rĂ©action 6Li+12C Ă 2 GeV/nuclĂ©on
Cette thĂšse prĂ©sente une nouvelle approche expĂ©rimentale proposĂ©e par la collaboration HypHI pour l Ă©tude des hypernoyaux dans des rĂ©actions induites par des faisceaux d ions lourds stables ou radioactifs. La mĂ©thode proposĂ©e permet de mesurer les hypernoyaux formĂ©s par coalescence entre un hypĂ©ron produit dans la rĂ©gion des participants et un fragment spectateur issu du projectile. Ce mode de production offre la possibilitĂ© d Ă©tudier les hypernoyaux dans des conditions extrĂȘmes d isospin et de mesurer directement leur moment magnĂ©tique hypernuclĂ©aire. Une premiĂšre expĂ©rience ayant pour objectif principal de dĂ©montrer la faisabilitĂ© de la nouvelle mĂ©thode proposĂ©e, a Ă©tĂ© rĂ©alisĂ©e en effectuant une spectroscopie prĂ©cise des hypernoyaux 4 H, 3 H et 5 He produits dans les collisions 6Li+12C Ă une Ă©nergie incidente de 2 GeV par nuclĂ©on. La conception, le dĂ©veloppement et la rĂ©alisation du nouveau dispositif de dĂ©tection sont prĂ©sentĂ©s. Les performances des dĂ©tecteurs, ainsi que celles du systĂšme de dĂ©clenchement ont Ă©tĂ© Ă©tudiĂ©es. Le code d analyse dĂ©veloppĂ© pour la reconstruction des hypernoyaux est prĂ©sentĂ© ainsi que ses performances sur les donnĂ©es simulĂ©es. L analyse des donnĂ©es expĂ©rimentales et les premiers rĂ©sultats de la reconstruction de l hypĂ©ron et de l hypernoyau 5 He, ainsi que la mesure de leur temps de vie, sont prĂ©sentĂ©s. Ces premiers rĂ©sultats dĂ©montrent la faisabilitĂ© de cette nouvelle approche expĂ©rimentale pour l Ă©tude des hypernoyaux et ouvrent de nouvelles perspectives dans la recherche d hypernoyaux lourds et proches des limites de stabilitĂ©.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 Î 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 "AtracciĂłn de
Talento Investigador" of the Community of Madrid
A novel method for the measurement of half-lives and decay branching ratios of exotic nuclei
A novel method for simultaneous measurement of masses, Q-values, isomer excitation energies, half-lives and decay branching ratios of exotic nuclei has been demonstrated. The method includes first use of a stopping cell as an ion trap, combining storage of mother and daughter nuclides for variable durations in a cryogenic stopping cell (CSC), and afterwards the identification and counting of them by a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS). We utilized our method to record the decay and growth of the 216Po and 212Pb isotopes (alpha decay) and of the 119m2Sb isomer ( t1/2=850±90 ms) and 119gSb isotope (isomer transition), obtaining half-lives consistent with literature values. The amount of non-nuclear-decay losses in the CSC up to âŒ10 s is negligible, which exhibits its extraordinary cleanliness. For 119Sb isotopes, we present the first direct measurements of the mass of its ground state, and the excitation energy and decay branching ratios of its second isomeric state (119m2Sb). This resolves discrepancies in previous excitation energy data, and is the first direct evidence that the 119m2Sb isomer decays dominantly via Îł emission. These results pave the way for the measurement of branching ratios of exotic nuclei.peerReviewe
Trauma Hemostasis and Oxygenation Research Network position paper on the role of hypotensive resuscitation as part of remote damage control resuscitation
The Trauma Hemostasis and Oxygenation Research (THOR) Network has developed a consensus statement on the role of permissive hypotension in remote damage control resuscitation (RDCR). A summary of the evidence on permissive hypotension follows the THOR Network position on the topic. In RDCR, the burden of time in the care of the patients suffering from noncompressible hemorrhage affects outcomes. Despite the lack of published evidence, and based on clinical experience and expertise, it is the THOR Networkâs opinion that the increase in prehospital time leads to an increased burden of shock, which poses a greater risk to the patient than the risk of rebleeding due to slightly increased blood pressure, especially when blood products are available as part of prehospital resuscitation.The THOR Networkâs consensus statement is, âIn a casualty with life-threatening hemorrhage, shock should be reversed as soon as possible using a blood-based HR fluid. Whole blood is preferred to blood components. As a part of this HR, the initial systolic blood pressure target should be 100 mm Hg. In RDCR, it is vital for higher echelon care providers to receive a casualty with sufficient physiologic reserve to survive definitive surgical hemostasis and aggressive resuscitation. The combined use of blood-based resuscitation and limiting systolic blood pressure is believed to be effective in promoting hemostasis and reversing shock