Experimental Discovery of a Tetraneutron – An Exotic State of Matter

Artists Concept Tetraneutron

Scientists have announced the experimental discovery of a tetraneutron, a new and exotic state of matter that could also have properties that are useful in existing or emerging technologies.

Theoretical physicist James Vary has been waiting for nuclear physics experiments to confirm the reality of a “tetraneutron” that he and his colleagues theorized, predicted, and first announced during a presentation in the summer of 2014, followed by a research paper in the fall of 2016.

“Whenever we present a theory, we always have to say we’re waiting for experimental confirmation,” said Vary, an Iowa State University professor of physics and astronomy.

In the case of four neutrons (very, very) briefly bound together in a temporary quantum state or resonance, that day for Vary and an international team of physicists is now here.

The just-announced experimental discovery of a tetraneutron by an international group led by scientists from Germany’s Technical University of Darmstadt opens doors for new research and could lead to a better understanding of how the universe is put together. This new and exotic state of matter could also have properties that are useful in existing or emerging technologies.

Theoretical Calculations Predicted Tetraneutron

Andrey Shirokov, left, of Moscow State University in Russia, who has been a visiting scientist at Iowa State, and James Vary of Iowa State are part of an international team of nuclear physicists who theorized, predicted and announced a four-neutron structure in 2014 and 2016. Credit: Christopher Gannon/Iowa State’s College of Liberal Arts and Sciences

First, how about a definition

Neutrons, you probably remember from science class, are subatomic particles with no charge that combine with positively charged protons to make up the nucleus of an atom. Well, individual neutrons aren’t stable and after a few minutes convert into protons. Combinations of double and triple neutrons also don’t form what physicists call a resonance, a state of matter that is temporarily stable before it decays.

Enter the tetraneutron

Using the supercomputing power at the Lawrence Berkeley National Laboratory in California, the theorists calculated that four neutrons could form a resonant state with a lifetime of just 3×10^(-22) seconds, less than a billionth of a billionth of a second. It’s hard to believe, but that’s long enough for physicists to study.

Tetraneutron’s Energy and Width

This graph shows experimental measurements and theoretical predictions for the tetraneutron’s energy and width, essential properties of this exotic state of matter. The measurements are in millions of electron volts, a common unit of measurement in high-energy and nuclear physics. The most recent experimental results are second from the left and labelled 2022. The theoretical predictions by the research group that includes Iowa State’s James Vary are the four columns labelled “NCSM” and represent results from different realistic inter-neutron interactions. These results were published in 2016 and 2018. The theoretical predictions labelled “GSM” were published in 2019 by a group based in China. They use a different method that complements the NCSM method. Publication details are also listed. Credit: James Vary/Iowa State University

A detail or two

The theorists’ calculations say the tetraneutron should have an energy of about 0.8 million electron volts (a unit of measurement common in high-energy and nuclear physics – visible light has energies of about 2 to 3 electron volts.) The calculations also said the width of the plotted energy spike showing a tetraneutron would be about 1.4 million electron volts. The theorists published subsequent studies that indicated the energy would likely lie between 0.7 and 1.0 million electron volts while the width would be between 1.1 and 1.7 million electron volts. This sensitivity arose from adopting different available candidates for the interaction between the neutrons.

A just-published paper in the journal Nature reports that experiments at the Radioactive Isotope Beam Factory at the RIKEN research institute in Wako, Japan, found tetraneutron energy and width to be around 2.4 and 1.8 million electron volts respectively. These are both larger than the theory results but Vary said uncertainties in the current theoretical and experimental results could cover these differences.

Why it’s a big deal

“A tetraneutron has such a short life it’s a pretty big shock to the nuclear physics world that its properties can be measured before it breaks up,” Vary said. “It’s a very exotic system.”

It is, in fact, “a whole new state of matter,” he said. “It’s short-lived, but points to possibilities. What happens if you put two or three of these together? Could you get more stability?”

Experiments trying to find a tetraneutron started in 2002 when the structure was proposed in certain reactions involving one of the elements, a metal called beryllium. A team at RIKEN found hints of a tetraneutron in experimental results published in 2016.

“The tetraneutron will join the neutron as only the second chargeless element of the nuclear chart,” Vary wrote in a project summary. That “provides a valuable new platform for theories of the strong interactions between neutrons.”

The papers, please

Meytal Duer of the Institute for Nuclear Physics at the Technical University of Darmstadt is the corresponding author of the Nature paper — “Observation of a correlated free four-neutron system” — announcing the experimental confirmation of a tetraneutron. The experiment’s results are considered a five-sigma statistical signal, denoting a definitive discovery with a one in 3.5 million chance the finding is a statistical anomaly.

The theoretical prediction was published October 28, 2016, in the journal Physical Review Letters (Prediction for a Four-Neutron Resonance). Andrey Shirokov of the Skobeltsyn Institute of Nuclear Physics at Moscow State University in Russia, who has been a visiting scientist at Iowa State, is the first author. Vary is one of the corresponding authors. Grants from the U.S. Department of Energy, the National Energy Research Scientific Computing Center, the Germany and U.S. Nuclear Theory Exchange Program and the Russian Science Foundation supported the theoretical work.

Written with a smile

“Can we create a small neutron star on Earth?” Vary titled a summary of the tetraneutron project. A neutron star is what’s left when a massive star runs out of fuel and collapses into a super-dense neutron structure. The tetraneutron is also a neutron structure, one Vary quips is a “short-lived, very-light neutron star.”

A personal reaction

“I had pretty much given up on the experiments,” Vary said. “I had heard nothing about this during the pandemic. This came as a big shock. Oh my God, here we are, we may actually have something new.”

Reference: “Observation of a correlated free four-neutron system” by M. Duer, T. Aumann, R. Gernhäuser, V. Panin, S. Paschalis, D. M. Rossi, N. L. Achouri, D. Ahn, H. Baba, C. A. Bertulani, M. Böhmer, K. Boretzky, C. Caesar, N. Chiga, A. Corsi, D. Cortina-Gil, C. A. Douma, F. Dufter, Z. Elekes, J. Feng, B. Fernández-Domínguez, U. Forsberg, N. Fukuda, I. Gasparic, Z. Ge, J. M. Gheller, J. Gibelin, A. Gillibert, K. I. Hahn, Z. Halász, M. N. Harakeh, A. Hirayama, M. Holl, N. Inabe, T. Isobe, J. Kahlbow, N. Kalantar-Nayestanaki, D. Kim, S. Kim, T. Kobayashi, Y. Kondo, D. Körper, P. Koseoglou, Y. Kubota, I. Kuti, P. J. Li, C. Lehr, S. Lindberg, Y. Liu, F. M. Marqués, S. Masuoka, M. Matsumoto, J. Mayer, K. Miki, B. Monteagudo, T. Nakamura, T. Nilsson, A. Obertelli, N. A. Orr, H. Otsu, S. Y. Park, M. Parlog, P. M. Potlog, S. Reichert, A. Revel, A. T. Saito, M. Sasano, H. Scheit, F. Schindler, S. Shimoura, H. Simon, L. Stuhl, H. Suzuki, D. Symochko, H. Takeda, J. Tanaka, Y. Togano, T. Tomai, H. T. Törnqvist, J. Tscheuschner, T. Uesaka, V. Wagner, H. Yamada, B. Yang, L. Yang, Z. H. Yang, M. Yasuda, K. Yoneda, L. Zanetti, J. Zenihiro and M. V. Zhukov, 22 June 2022, Nature.
DOI: 10.1038/s41586-022-04827-6

The theorists

In addition to Vary and Shirokov, others involved in the theoretical prediction of a tetraneutron were George Papadimitriou of Lawrence Livermore National Laboratory in California (and a former postdoctoral research associate at Iowa State); Alexander Mazur of Pacific National University in Khabarovsk, Russia; Igor Mazur, also of Pacific National University; and Robert Roth of Technical University of Darmstadt in Germany.

9 Comments on "Experimental Discovery of a Tetraneutron – An Exotic State of Matter"

  1. Daniel Nittmann | June 24, 2022 at 3:17 am | Reply

    Let me guess they removed the osmium from a tetrahytrate via lichbogangessmolderzine with black noise between four refractive prisms,. A plasmoidial crystalline matrix also extrapolated from b5 infra red emitters via cyclotron accumulation into Bose eienstien condensate in inductance of rotation lines of interferance cyamatically

    • You are on the button Daniel! I personally tried my best to encourage Slartibastfast and Zaphod to keep on banging the rocks together. 😆🧐

  2. Olá, meu nome é Marcelo jubilado Catharino criei 2 teorias, uma teoria de 2 átomos em movimento quântico em singularidade infinita para dentro de si e para qualquer direção. Explico as duas teorias no meu livro Caos do passado sendo vívido no futuro e a outra de 1 átomo em movimento em singularidade onde temos o relógio (tempo é a marcação da propagação da energia), símbolos do zodíacos, estrela de Davi e outras teorias do movimento de si próprio.
    Dentro dessas duas teorias, todas as teorias se encaixam, desde arquétipos platônicos, Fibonacci, cristal do tempo (átomos sendo comprimidos até ficar em singularidade), darwinismo quântico, Tesla, Einstein, Sócrates, todas as formas de captação religiosa e tudo que contém movimento .
    Na minha teoria eu digo que tudo que contém matéria, física e tudo que existe contém vida.
    Logo eu percebo que a diferença entre nós humanos e qualquer coisa existente é conseguir interpretar a morte, pois tudo que existe passa por caos para adpatar-se, dentro dessa adaptação caótica contém “registros” de DNA, gravidade, forças, física, física quântica e todas as energias existente no universo.
    Quando ocorreu o início do universo, sua origem teve uma grande liberação de energia e essa energia veio derivada de um grande movimento inicial, qual é o valor desse movimento inicial e quanto tempo leva para ele adaptar-se?
    logo vejo que aquele movimento inicial é o movimento que controla todo universo em adpatar-se e ficar em singularidade.
    Qual é a quantidade de caos no universo?
    Dentro desses movimentos de adaptação qual é a energia de maior força? universo, galáxia, sistema solar, terra ou humanos…
    Quem precisa adaptar-se, nós humanos ou o universo adaptar a nós humanos?

  3. Hello, my name is Marcelo jubilado Catharino I created 2 theories, a theory of 2 atoms in quantum motion in infinite singularity towards itself and towards any direction. I explain the two theories in my book Chaos of the past being vivid in the future and the other of 1 moving atom in singularity where we have the clock (time is the marking of the propagation of energy), zodiac symbols, star of David and other theories of the self movement. Within these two theories, all theories fit, from Platonic archetypes, Fibonacci, time crystal (atoms being compressed into singularity), quantum Darwinism, Tesla, Einstein, Socrates, all forms of religious capture and everything that contains movement. . In my theory I say that everything that contains matter, physics and everything that exists contains life. Soon I realize that the difference between us humans and anything that exists is to be able to interpret death, because everything that exists goes through chaos to adapt, within this chaotic adaptation contains “records” of DNA, gravity, forces, physics, quantum physics and all energies existing in the universe. When the beginning of the universe occurred, its origin had a great release of energy and that energy came from a great initial movement, what is the value of this initial movement and how long does it take for it to adapt? I soon see that that initial movement is the movement that controls the entire universe in adapting and staying in singularity. How much chaos is in the universe? Within these adaptation movements, what is the most powerful energy? universe, galaxy, solar system, earth or humans… Who needs to adapt, we humans or the universe adapt to us humans?

  4. Maybe these things could be the excitons in some insane lasing device.

  5. now imagine a bunch of these… can they connect together to make a force field…
    I think the reason why they connect together in the first place is because the photonic voltage or electric field negative and positive cancel out and make the nuclear weak force; and the photonic current or magnetic field north and south cancel out to make the nuclear strong force;
    so in string theory we can break everything down to electric and magnetic waves in our dimension and anti-electric and anti-magnetic waves in the reverse time dimension where all the antimatter is so far out in space, time reverses into the symmetrical continuum .. which is why gravity is actually a continuum (like time) flow of both time dimensions; more mass controls the amount of energy flow that when viewed together reveals the “string theory” picture of protons neutrons! with photonic energy making up the electromagnetic fields and nuclear weak and nuclear strong forces, that when smashed together we get up quarks and down quarks, so the other side of a
    black-hole is a white-hole in the reverse time dimension, and space as a invisible photon spinning a quantum continuum , yes I cant comprehend fully yet a idea of a past that hasn’t happened yet entangled with a future that hasn’t happened yet… [email protected]

  6. How is all this information going to explain how a neutron star exists? Neutrons have no charge yet they they represent the most dense stars in the universe. What keeps them together if they have no charge to keep them together?

    When a black hole cools, its first stage is turning into a neutron star. Black holes are optically invisible at first because all they emit are gamma rays. Black holes are made of nothing but quarks and use dark matter that causes gravity as the catalyst. They are the most simple, yet powerful, masses of plasma that exist. Since dark matter is the catalyst, they can run for virtually forever. That is why it is this plasma that makes the energy in our universe seem timeless.
    Dark matter is an extremely pressurized field of sterile electron neutrinos. A black hole shows entropy by finally combining the quarks and neutrinos on the surface to create the first neutrons the mass will possess. The neutron star is still a black hole but with a very thin layer of neutrons on the surface. These neutrons give the black holes their first visible light because there is finally resistance out upon the gamma rays.
    Once the surface of the black hole is filled with neutrons, they start decaying into the first hydrogen the mass will possess. At that point, the constantly forming neutrons fuse with the hydrogen to create helium on the surface using the beta minus decay reaction. Those constantly forming neutrons continue this process creating heavier elements making the star darker since more resistance is present. Eventually, the light goes out and a surface forms. This is when the atmosphere is allowed to develop.

    It is the Big Bang theory that keeps science from understanding everything in physics that is currently not understood. Clouds of normal matter do not create stars with gravity. That would make gravity a “free energy” which is impossible. What truly created all the energy we see was the pressure and friction from a massive collision in space. Just as particle colliders create quark plasma shrapnel, our universe created quark plasma shrapnel as the expanding galaxies. Each galaxy was created as an initial mass of quark plasma. Energy creates gravity, gravity doesn’t create energy. This is why the force of gravity remains unexplained to this day.
    Neutron stars emit so much energy because they are black holes right underneath their surface. Black holes are able to keep neutrons on their surface because of the massive radiation flowing out of the mass. Based on this article, neutron stars should not be able to exist.
    Edwin Hubble discovered the galaxies expanding because they are shrapnel from a massive collision. That explanation is the beginning of the “Theory of Everything”. All the other questions that have never been answered can be answered with this one, law-abiding explanation.

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