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Lazauskas R, Hiyama E, Carbonell J. Low Energy Structures in Nuclear Reactions with 4n in the Final State. PHYSICAL REVIEW LETTERS 2023; 130:102501. [PMID: 36962048 DOI: 10.1103/physrevlett.130.102501] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 11/16/2022] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
We investigate a reaction model that describes a fast removal of the α particle from the ^{8}He nucleus with eventual emission of four neutrons. The obtained four neutron energy distribution allows one to explain the sharp low energy peak observed by studying the missing mass spectra of four neutrons in Duer et al. [Nature (London) 606, 678 (2022)NATUAS0028-083610.1038/s41586-022-04827-6], as a consequence of dineutron-dineutron correlations. The phenomenon of the emergence of a sharp low-energy peak in the four-neutron energy distribution should be more general and is expected in the decay of other systems containing a four-neutron halo.
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Affiliation(s)
- Rimantas Lazauskas
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Emiko Hiyama
- Department of Physics, Tohoku University, Sendai 980-8578, Japan and RIKEN Nishina Center, Wako 351-0198, Japan
| | - Jaume Carbonell
- Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France
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2
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Xu F. Can a pure neutron state of matter exist? Sci Bull (Beijing) 2022; 67:2487-2489. [PMID: 36604020 DOI: 10.1016/j.scib.2022.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Furong Xu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China.
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Abstract
A long-standing question in nuclear physics is whether chargeless nuclear systems can exist. To our knowledge, only neutron stars represent near-pure neutron systems, where neutrons are squeezed together by the gravitational force to very high densities. The experimental search for isolated multi-neutron systems has been an ongoing quest for several decades1, with a particular focus on the four-neutron system called the tetraneutron, resulting in only a few indications of its existence so far2–4, leaving the tetraneutron an elusive nuclear system for six decades. Here we report on the observation of a resonance-like structure near threshold in the four-neutron system that is consistent with a quasi-bound tetraneutron state existing for a very short time. The measured energy and width of this state provide a key benchmark for our understanding of the nuclear force. The use of an experimental approach based on a knockout reaction at large momentum transfer with a radioactive high-energy 8He beam was key. Experiment based on knocking out an alpha particle from a high-energy helium isotope shows a resonance-like structure that is consistent with a quasi-bound tetraneutron state existing for a very short time.
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Higgins MD, Greene CH, Kievsky A, Viviani M. Nonresonant Density of States Enhancement at Low Energies for Three or Four Neutrons. PHYSICAL REVIEW LETTERS 2020; 125:052501. [PMID: 32794850 DOI: 10.1103/physrevlett.125.052501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/26/2020] [Accepted: 07/06/2020] [Indexed: 06/11/2023]
Abstract
The low energy systems of three or four neutrons are treated within the adiabatic hyperspherical framework, yielding an understanding of the low energy quantum states in terms of an adiabatic potential energy curve. The dominant low energy potential curve for each system, computed here using widely accepted nucleon-nucleon interactions with and without the inclusion of a three-nucleon force, shows no sign of a low energy resonance. However, both systems exhibit a low energy enhancement of the density of states, or of the Wigner-Smith time delay, which derives from long-range universal physics analogous to the Efimov effect. That enhancement could be relevant to understanding the low energy excess of correlated four-neutron ejection events observed experimentally in a nuclear reaction by Kisamori et al. [Phys. Rev. Lett. 116, 052501 (2016)PRLTAO0031-900710.1103/PhysRevLett.116.052501].
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Affiliation(s)
- Michael D Higgins
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - Chris H Greene
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA and Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana 47907, USA
| | - A Kievsky
- Instituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, 56127 Pisa, Italy
| | - M Viviani
- Instituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, 56127 Pisa, Italy
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Gandolfi S, Hammer HW, Klos P, Lynn JE, Schwenk A. Gandolfi et al. Reply. PHYSICAL REVIEW LETTERS 2019; 123:069202. [PMID: 31491169 DOI: 10.1103/physrevlett.123.069202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Indexed: 06/10/2023]
Affiliation(s)
- S Gandolfi
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - H-W Hammer
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - P Klos
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - J E Lynn
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - A Schwenk
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
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Kravvaris K, Volya A. Study of Nuclear Clustering from an Ab Initio Perspective. PHYSICAL REVIEW LETTERS 2017; 119:062501. [PMID: 28949635 DOI: 10.1103/physrevlett.119.062501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Indexed: 06/07/2023]
Abstract
We put forward a new ab initio approach that seamlessly bridges the structure, clustering, and reactions aspects of the nuclear quantum many-body problem. The configuration interaction technique combined with the resonating group method based on a harmonic oscillator basis allows us to treat the reaction and multiclustering dynamics in a translationally invariant way and preserve the Pauli principle. Our presentation includes studies of ^{8,10}Be and an exploration of 3α clustering in ^{12}C.
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Affiliation(s)
| | - Alexander Volya
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
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Fossez K, Rotureau J, Michel N, Płoszajczak M. Can Tetraneutron be a Narrow Resonance? PHYSICAL REVIEW LETTERS 2017; 119:032501. [PMID: 28777610 DOI: 10.1103/physrevlett.119.032501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Indexed: 06/07/2023]
Abstract
The search for a resonant four-neutron system has been revived thanks to the recent experimental hints reported in [1]. The existence of such a system would deeply impact our understanding of nuclear matter and requires a critical investigation. In this work, we study the existence of a four-neutron resonance in the quasistationary formalism using ab initio techniques with various two-body chiral interactions. We employ no-core Gamow shell model and density matrix renormalization group method, both supplemented by the use of natural orbitals and a new identification technique for broad resonances. We demonstrate that while the energy of the four-neutron system may be compatible with the experimental value, its width must be larger than the reported upper limit, supporting the interpretation of the experimental observation as a reaction process too short to form a nucleus.
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Affiliation(s)
- K Fossez
- NSCL/FRIB Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Rotureau
- NSCL/FRIB Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- JINPA, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - N Michel
- NSCL/FRIB Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - M Płoszajczak
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, BP 55027, F-14076 Caen Cedex, France
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