A new experiment using rare-isotope beams has provided new insight into the origin of proton-rich isotopes known as p-nuclei.
Researchers have taken an important step toward solving one of astrophysics’ oldest isotope mysteries: where the rare proton-rich atomic species known as p-nuclei come from.
The study was led by Artemis Tsantiri, who conducted the work as a graduate student at the Facility for Rare Isotope Beams (FRIB) and is now a postdoctoral fellow at the University of Regina in Canada.
The team carried out the first rare isotope beam measurement of proton capture on arsenic-73, a reaction that produces selenium-74. Their findings place new limits on how the lightest p-nucleus forms and is destroyed in space. The results were published in Physical Review Letters. More than 45 researchers from 20 institutions across the United States, Canada, and Europe contributed to the project.
One of the central questions in nuclear astrophysics is how the elements in the universe are created. Many elements heavier than iron form through two well-known processes. In both cases, atomic nuclei repeatedly capture neutrons and then undergo radioactive decay until they reach stable isotopes.
However, these neutron-capture processes cannot explain a group of proton-rich isotopes known as p-nuclei. These rare isotopes range from selenium-74, the lightest, to mercury-196, the heaviest.
Supernova Gamma Process
Scientists have proposed several possible environments where p-nuclei might form. The leading explanation is the gamma process, which occurs during certain types of supernova explosions.
During these events, extremely high temperatures generate intense gamma radiation that strips neutrons and other particles from existing heavy nuclei. Afterward, the remaining nuclei contain more protons than neutrons. Over time, nuclear transformations convert some protons into neutrons, shifting the nucleus toward a more stable neutron-to-proton balance and ultimately producing a p-nucleus.
Many of the nuclei involved in the gamma process are rare isotopes. Because they are difficult to create in the laboratory, many of their properties remain poorly measured. As a result, models of the gamma process often rely heavily on theoretical estimates.
“Even though the origin of the p-nuclei has been a topic of study for over 60 years, measurements of important reactions on short-lived isotopes are almost non-existent,” said Tsantiri. “Experiments of this kind are only now possible with facilities like FRIB.”
Measuring a Key Reaction
In the new experiment, researchers directly studied how the radioactive isotope arsenic-73 captures a proton to form selenium-74. This measurement was achieved in the laboratory for the first time.
Scientists produced a beam of arsenic-73 specifically for the experiment and directed it into a small chamber filled with hydrogen gas. The hydrogen served as the proton target and was positioned at the center of the Summing NaI (SuN) detector.
To perform the measurement, the team obtained radioactive arsenic-73 and operated FRIB’s ReA accelerator in standalone mode rather than receiving beams from the main FRIB linear accelerator. The radiochemistry group, led by Katharina Domnanich, assistant professor of chemistry at FRIB and in MSU’s Department of Chemistry, prepared the isotope in a suitable chemical form.
The material was placed into FRIB’s batch-mode ion source. There, arsenic-73 ions were extracted, accelerated to high energies, and delivered to the experiment. The work demonstrated that the ReA accelerator can generate arsenic-73 beams in offline mode, providing researchers with greater flexibility for future studies.
Insights Into Selenium-74
In the reaction observed in the experiment, arsenic-73 absorbs a proton and forms selenium-74 in an excited state. The nucleus then emits a gamma ray as it settles into a more stable configuration.
The researchers focused on the inverse reaction, which occurs during the gamma process in stars. Its rate can be determined by measuring the direct proton-capture reaction in the laboratory. To explain the observed abundance of any isotope, scientists must consider both the processes that produce it and those that destroy it.
For selenium-74, the largest remaining nuclear physics uncertainty affecting its estimated abundance in the solar system involves its destruction by gamma rays during the gamma process.
When the researchers incorporated their experimental data into an astrophysical model of the gamma process, the uncertainty in the predicted relative abundance of selenium-74 decreased by a factor of two. Despite this improvement, the model still does not fully reproduce the observed abundance of selenium-74. The result suggests that existing models of the astrophysical conditions driving the gamma process may need revision.
“These results bring us a step closer to understanding the origins of some of the rarest isotopes in the universe,” said Artemis Spyrou, professor of physics at FRIB and in the Michigan State University Department of Physics and Astronomy, research advisor to Tsantiri, and original architect of the experiment. “Tsantiri’s work is a nice example of the multidisciplinary collaborations needed for advancing the field, and of the kind of professional development opportunities for early career researchers at FRIB.”
Reference: “Constraining the Synthesis of the Lightest p Nucleus Se74” by A. Tsantiri, A. Spyrou, E. C. Good, K. Bosmpotinis, P. Giuliani, H. Arora, G. Balk, L. Balliet, H. C. Berg, J. M. Berkman, C. Dembski, P. DeYoung, Pavel A. Denissenkov, N. Dimitrakopoulos, A. Doetsch, T. Gaballah, R. Garg, A. Henriques, R. Jain, S. N. Liddick, S. Lyons, R. S. Lubna, B. Monteagudo Godoy, F. Montes, S. Nash, G. U. Ogudoro, J. Owens-Fryar, A. Palmisano-Kyle, J. Pereira, A. Psaltis, A. L. Richard, L. Roberti, E. K. Ronning, H. Schatz, A. Sebastian, M. Smith, M. K. Smith, C. S. Sumithrarachchi, C. Tinson, P. Tsintari, N. Tubaro, S. Uthayakumaar, A. C. C. Villari, E. Weissling and R. G. T. Zegers, 20 November 2025, Physical Review Letters.
DOI: 10.1103/d7dr-h36j
The work was supported in part by funding from the U.S. Department of Energy Office of Science Office of Nuclear Physics; the U.S. National Science Foundation; the U.S. National Nuclear Security Administration; and the Natural Sciences and Engineering Research Council of Canada.
The isotope(s) used in this research was supplied by the U.S. Department of Energy Isotope Program, managed by the Office of Isotope R&D and Production.
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4 Comments
The result suggests that existing models of the astrophysical conditions driving the gamma process may need revision.
VERY GOOD!
Please ask researchers to think deeply:
Mathematically speaking, do particles in space come from the topological evolution of space itself or from God? Can humans observe all the fundamental particles in space? Has the Standard Model already covered all fundamental particles? Where does the driving force behind the evolution of elementary particles come from?
When we pursue the ultimate truth of all things, the space in which our bodies and all things exist may itself be the final and deepest puzzle we need to explore. This is not only the pursuit of physics, but also the most magnificent exploration of the origin of the universe by human reason.
Based on the Topological Vortex Theory (TVT), space is an uniformly incompressible physical entity. Space-time vortices are the products of topological phase transitions of the tipping points in space, are the point defects in spacetime. Point defects do not only impact the thermodynamic properties, but are also central to kinetic processes. They create all things and shape the world through spin and self-organization.
In today’s physics, some so-called peer-reviewed journals—including Physical Review Letters, Nature, Science, and others—stubbornly insist on and promote the following:
1. Even though θ and τ particles exhibit differences in experiments, physics can claim they are the same particle. This is science.
2. Even though topological vortices and antivortices have identical structures and opposite rotational directions, physics can define their structures and directions as entirely different. This is science.
3. Even though two sets of cobalt-60 rotate in opposite directions and experiments reveal asymmetry, physics can still define them as mirror images of each other. This is science.
4. Even though vortex structures are ubiquitous—from cosmic accretion disks to particle spins—physics must insist that vortex structures do not exist and require verification. Only the particles that like God, Demonic, or Angelic are the most fundamental structures of the universe. This is science.
5. Even though everything occupies space and maintains its existence in time, physics must still debate and insist on whether space exists and whether time is a figment of the human mind. This is science.
6. Even though space, with its non-stick, incompressible, and isotropic characteristics, provides a solid foundation for the development of physics, physics must still insist that the ideal fluid properties of space do not exist. This is science.
and go on.
Is this the counterintuitive science they widely promote? Compromising with pseudo academic publications and peer review by pseudo scholars is an insult to science and public intelligence. Some so-called scholars no longer understand what shame is. The study of Topological Vortex Theory (TVT) reminds us that the most profound problems in physics often lie at the intersection of different theories. By exploring these border regions, we can not only resolve contradictions in existing theories but also discover new physical phenomena and application possibilities.
Under the topological vortex architecture, it is highly challenging for even two hydrogen atoms or two quarks to be perfectly symmetrical, let alone counter-rotating two sets of cobalt-60. Contemporary physics and so-called peer-reviewed publications (including Physical Review Letters, Science, Nature, etc.) stubbornly believe that two sets of counter rotating cobalt-60 are two mirror images of each other, constructing a more shocking pseudoscientific theoretical framework in the history of science than the “geocentric model”. This pseudo scientific framework and system have seriously hindered scientific progress and social development.
For nearly a century, physics has been manipulated by this pseudo scientific theoretical system and the interest groups behind it, wasting a lot of manpower, funds, and time. A large amount of pseudo scientific research has been conducted, and countless pseudo scientific papers have been published, causing serious negative impacts on scientific and social progress, as well as humanistic development.
Complexity does not necessarily mean that there is no logical and architectural framework to follow. Mathematics is the language and tool that reveals the motion of spacetime, rather than the motion itself. Although the physical form of spacetime vortices is extremely simple, their interaction patterns are highly complex, and we must develop more and richer mathematical languages to describe and understand them.
The development of the Topological Vortex Theory (TVT) reflects a progression from concrete physical phenomena to abstract mathematical modeling and, ultimately, to interdisciplinary unification. Its core innovation lies in forging the continuous spacetime geometry of general relativity with the discrete interactions of quantum field theory within the same topological dynamical system. The core idea of TVT — space is physical, and matter is its topological excitation—already provides a solid and elegant scientific path for understanding the origin of all things.
——Excerpted from https://scitechdaily.com/microscope-spacecrafts-most-precise-test-of-key-component-of-the-theory-of-general-relativity/#comment-909171 and https://t.pineal.cn/blogs/6255/A-Mathematical-and-Physical-Analysis-On-the-Origin-of-Objects.
Are these science?
Example 1
Two sets of cobalt-60 are manually rotated in opposite directions, and even without detection, people around the world know that they will not be symmetrical because these two objects are not mirror images of each other at all. However, a group of so-called physicists and so-called academic publications do not believe it. They conducted experiments and the results were indeed asymmetric, but they still firmly believed that these two objects were mirror images of each other, and the asymmetry was due to a violation of the previous natural laws (CP violation). In the history of science, there can never be a dirtier and uglier operation and explanation than this.
—— Excerpted from https://scitechdaily.com/what-happens-when-light-gains-extra-dimensions/#comment-947619.
Example 2
Please see how the so-called “mystery of θ – τ” is explained: θ and τ are completely identical in all measurable physical properties such as mass, lifetime, charge, spin, etc. However, experimental observations have shown that the θ meson decays into two π mesons, while the τ meson decays into three π mesons, making it difficult for physicists to explain why they are so similar. Physicist Martin Block proposed a highly challenging idea: θ and τ are the same particle, but in weak interactions, parity is not conserved. An easy to understand explanation is the following analogy:: There are two boxes of apples with identical weight, color, and taste. However, when one box is opened, there are two apples, while when the other box is opened, there are three apples. This confuses the old farmer who buys apples. He circled around the orchard and came up with a highly challenging idea: these two boxes of apples are not from the same tree, so they are the same.
—— Excerpted from https://scitechdaily.com/what-happens-when-light-gains-extra-dimensions/#comment-947686.
Everyone who has a reverence for natural laws and regulations deserves respect.
In the physical world constructed by the American Physical Society (APS) and its publications using parity violation, particles from God, Demons, and Angels wander around, while dead and alive cats jump up and down, unconstrained by dynamics and thermodynamics, and unaware of what is dirty, ugly, and shameful in public. APS and its publications reject the possibility that spaces with zero viscosity, zero compression, and zero anisotropy in mathematics may form spatiotemporal vortices through topological transformations. They don’t know that space and non existence are not the same concept.
Based on the Topological Vortex Theory (TVT), the morphology and structure of elementary particles can vary in countless ways, which is an inevitable result of the evolution of spatiotemporal motion from low dimensions to high dimensions. The particles in the Standard Model are products of spatiotemporal vortex topological evolution. Nature always uses local symmetry changes to ensure global parity conservation. Expanding the local asymmetry caused by artificial simulation and observer effects infinitely into fundamental laws of nature (such as CP violation) is a serious conceptual and methodological error.
For nearly a century, so-called peer-reviewed publications led by the American Physical Society (APS) have been challenging the dignity of science with pseudoscientific theories. His behavior is unreasonable and unforgivable. If a self proclaimed scientific society (such as American Physical Society) deviates from science without shame, it is highly likely to be heading towards the end. Nature is the final court of appeal for science, and it is geometric, not merely numerical.
dude(or dudette, kinda hard to tell i apologise) sincerely i know getting published can be grueling and stressful but proposing ur theory in the COMMENT SECTION OF A NEWS ARTICLE is not helping ur credibility bud … i rly hope ur a bot cus imagining someone being at this for like 1.5 years from what i remember is like, rly sad
Thank you for your continuous browsing and current comments.
I believe the public is not fools.
I really don’t want to associate with some dirty and ugly people or publications anymore. Their dishonesty has caused serious harm to the development of science and seems to continue to do so.