Kaiser, J., Xu, C., Eichler, A. et al. Sci Rep 14, 15,733 (2024). https://doi.org/10.1038/s41598-024-66263-y.
Quantum theory describes events that take place on extremely short time scales. In the past, such events were regarded as ‘momentary’ or ‘instantaneous’: An electron orbits the nucleus of an atom—in the next moment it is suddenly ripped out by a flash of light. Two particles collide—in the next moment they are suddenly ‘quantum entangled.’
Scientists have synthesized an isotope of the superheavy element livermorium using a novel fusion reaction. The result paves the way for the discovery of new chemical elements.
How and where in the Universe are the chemical elements created? How can we explain their relative abundance? What is the maximum number of protons and neutrons that the nuclear force can bind in a single nucleus? Nuclear physicists and chemists expect to find answers to such questions by creating and studying new elements. But as elements get more and more massive, they become harder and harder to synthesize. The heaviest elements discovered so far were created by bombarding high-atomic-number (high-Z) actinide targets with beams of calcium-48 (48 Ca). This isotope is particularly suited to such experiments because of its peculiar nuclear configuration, in which the number of neutrons and protons are both “magic numbers.” Yet this approach could not produce elements beyond oganesson (proton number, Z = 118).
A new method for studying the behavior of multiparticle systems relies on a simple “head count” of particles in imaginary boxes.
One way to characterize the interactions in a bacterial colony or a polymer mixture is to trace the path of individual particles through the system, but such tracking can become difficult when the particles are indistinguishable. Researchers have developed a new method that extracts particle dynamics from a simple counting of particles in imaginary boxes of adjustable size [1]. They demonstrated this “countoscope” strategy in experiments with small plastic spheres moving around in a liquid. The measured rate of diffusion was different for different sized boxes, which revealed particle clumping. The countoscope’s ability to identify such collective behavior could one day help researchers understand the mechanisms that cause bacteria and other life forms to group together.
Biologists, chemists, and soft-matter physicists often study many-particle systems in which the particles shuffle around each other in a “random walk.” A useful measure of this behavior is the diffusion constant, which describes how fast an individual particle moves. A measurement of the diffusion constant can tell a biologist whether cells are healthy or sick, or it can tell a chemist how fast a molecule will move through a gel in a chemical-analysis device. The diffusion constant is typically determined by following the path of a single particle in a video recording. This trajectory reconstruction becomes difficult, however, when the particles are numerous and all look the same, says Sophie Marbach from Sorbonne University in France.
Predicting the behavior of many interacting quantum particles is a complex task, but it’s essential for unlocking the potential of quantum computing in real-world applications. A team of researchers, led by EPFL, has developed a new method to compare quantum algorithms and identify the most challenging quantum problems to solve.
Quantum systems, from subatomic particles to complex molecules, hold the key to understanding the workings of the universe. However, modeling these systems quickly becomes overwhelming due to their immense complexity. It’s like trying to predict the behavior of a massive crowd where everyone constantly influences everyone else. When you replace the crowd with quantum particles, you encounter what’s known as the “quantum many-body problem.”
Quantum many-body problems involve predicting the behavior of numerous interacting quantum particles. Solving these problems could lead to major breakthroughs in fields like chemistry and materials science, and even accelerate the development of technologies like quantum computers.
For many years, scientists believed that fundamental particles like protons and neutrons that form an atomic nucleus, can’t be divided further into smaller units. However, in the following years, physicists discovered quarks and gluons.
While quarks are particles that combine to form protons and neutrons, gluons act like glue, binding the quarks together.
So far, scientists have been studying the atomic nucleus using two models. In the first model, at low energies like in most typical nuclear experiments, they describe the atomic nucleus in terms of protons and neutrons. This is the classic way of understanding the nucleus.
Electromagnetic radiation of extremely high energies is produced not only in the jets launched from active nuclei of distant galaxies, but also in jet-launching objects lying within the Milky Way, called microquasars. This latest finding by scientists from the international High-Altitude Water Cherenkov Gamma-Ray Observatory (HAWC) radically changes the previous understanding of the mechanisms responsible for the formation of ultra-high-energy cosmic radiation and in practice marks a revolution in its further study.
Since the discovery of cosmic radiation by Victor Hess in 1912, astronomers have believed that the celestial bodies responsible in our galaxy for the acceleration of these particles up to the highest energies are the remains of gigantic supernova explosions, called supernova remnants.
However, a different picture comes from the latest data from the HAWC observatory: The sources of radiation of extremely high energies turn out to be microquasars. Astrophysicists from the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Cracow played a key role in the discovery.
While these findings, published in Physical Review Letters, did not lead to the observation of signals associated with these hypothetical dark matter particles, they established a new technique to search for axions using a tunable optical cavity.
A team of physicists from the universities of Amsterdam, Princeton and Oxford have shown that extremely light particles known as axions may occur in large clouds around neutron stars. These axions could form an explanation for the elusive dark matter that cosmologists search for—and moreover, they might not be too difficult to observe.
Axions—theorized particles that could account for dark matter—could accumulate around rapidly rotating neutron stars to the point that they become detectable.
