📰One more step towards the observation of the tetraneutron


A resonance structure compatible with a quasi-bonded tetraneutron was observed by scientists from the SAMURAI collaboration in RIKEN, Japan, involving a team from LPC Caen. This observation confirms the first clues obtained 20 years earlier at GANIL and will force us to reconsider the simulation models of nucleon cohesion in the atomic nucleus (The atomic nucleus refers to the region in the center of an atom consisting of …).

Representation of a tetraneutron. The unequivocal observation of this system composed of 4 neutrons generates a light (Light is the set of electromagnetic waves visible to the eye …) news on the mechanisms of cohesion in the atomic nucleus or in neutron stars.
Credit: CNRS / IN2P3

the neutron (A neutron is a subatomic particle with zero total electrical charge.) free to a time (Time is a concept developed by humans to learn the …) from life (Life is the name given 🙂 of 15 minutes (Primary form of a document: Law: one minute is the original of a …). On the other hand, it is stable when it is bound in nuclei or in neutron stars, compact and dense objects composed mainly of neutrons and which can only exist thanks to the gravitation (Gravitation is the phenomenon of physical interaction that causes attraction …). At full scale different (In mathematics, the different is defined in the algebraic theory of …) from that of neutron stars, an exciting search has been pursued for several decades, Research (Scientific research primarily refers to all actions undertaken with a view to …) very light systems composed of few neutrons.

At the beginning of the 2000s, measurements were made at GANIL and the first indications of the existence of a small aggregate composed of 4 neutrons were published: the “tetraneutron”. It was obtained from break (In mineralogy, the fracture designates the appearance of the surface of a mineral that, …) from the core 14Enter 10Be is a 4 neutron system. Is there such a neutral system? If so, is it related, even weakly, or is it a resonance (Resonance is a phenomenon whereby some physical systems …) ? Like, if so, theinteraction (An interaction is an exchange of information, affect or energy between two agents within …) nuclear (The term nuclear energy has two meanings depending on the context 🙂 allows you to bind this system where protons are absent? Indications of the existence of the tetraneutron, in a bound state or in a form of quasi-bound resonance, have been obtained in the following years, but no certainty has been established.

A rupture reaction causes the tetraneutron to appear

The same team from the Laboratory of Physicist (Physics (from the Greek φυσις, nature) is etymologically the …) The Corpusculaire de Caen (LPC Caen), responsible for the measurements made at GANIL about twenty years ago, has just published in the journal NATURE, as part of the SAMURAI collaboration, measurements made at the ‘Radioactive ion (An ion is an electrically charged chemical species. The term comes from the English, …) Beam Factory ‘at RIKEN in Japan. This is a breaking reaction, 8He (p, p4He) 4n, shown schematically in the following figure.

The target proton ejects an alpha (4He) particle from the core of the 8He projectile, leaving the remaining 4 neutrons unperturbed as a highly correlated resonant state.
Image: DUER ET AL / NATURA 2022

The proton from the target ejects an alpha particle (4He) of the bullet core of 8Him, leaving the remaining 4 neutrons undisturbed as a highly correlated resonant state. A resonance structure everything (The whole understood as the whole of what exists is often interpreted as the world or …) quite compatible with an almost bound tetraneutron has in fact been observed very clearly, after decades of research experimental (In art, these are creative approaches based on questioning dogmas …). L’power (In common sense, energy means anything that allows you to do work, produce energy, etc.) of the tetraneutron was reconstructed from an energy balance of the reaction, with the so-called method of mass (The term mass is used to designate two quantities linked to one …) missing, measuring the energy of the proton and the alpha particle.

Improve modeling of nuclear systems

Some theoretical studies in which nuclear interaction is treated in a more or less phenomenological way have shown that there could be a resonant tetraneutron, with a very short life. However, other more microscopic approaches called from the beginning, that is, formalized by the elementary interaction between neutrons, they do not predict such resonance. This experimental result therefore represents an important challenge: if it turns out that it is not possible to explain otherwise (than with the existence of a resonant tetraneutron) the strong correlation observed recently, the way to construct the nuclear interaction in the approaches from the beginning it should probably be revisited and formalized in a slightly different framework.

This result represents an important step that will allow, among other things, to test the way in which nuclear physicists describe the interaction between nucleons and consequently to improve the modeling of nuclear systems, not only nuclei, but also it matters (Matter is the substance that makes up any body having a tangible reality. Its …) infinite nuclear system ideal (In mathematics, an ideal is an algebraic structure defined in a ring ….) infinite (The word “infinity” (-e, -s; from the Latin finitus, …) composed of nucleons whose study helps to understand the properties of nuclei and neutron stars.

Learn more:
Publication: “Observation of a correlated system of four free neutrons” Nature volume (Volume, in the physical or mathematical sciences, is a quantity that measures the extent …) 606, pages 678-682 (2022) M. Duer et al, SAMURAI collaboration (LPC Caen: L. Achouri, J. Gibelin, FM Marqués, B. Monteagudo, NA Orr, M. Parlog, A. Revel)

Review article on tetraneutron research: “The quest for light multineutron systems”, European Physical Journal A 57 (2021) 105. FM Marqués, J. Carbonell,

– Miguel Marqués – Research Director at LPC Caen – trademarks at lpccaen.in2p3 (The National Institute of Nuclear Physics and Particle Physics (IN2P3) is an institute of …).Fr
– Marcella Grasso – DAS Nuclear physics (Nuclear physics is the science that studies not only the atomic nucleus as …) and applications – marcella.grasso on
– Emmanuel Jullien – Head of Unit communication (Communication concerns both man (intrapsychic, interpersonal communication, etc.) IN2P3 – communication on

Did you like this article? Do you want to support us? Share it on social networks with your friends and / or comment on it, this will encourage us to post more similar topics!


Leave a Comment