In a first, US researchers have observed fractional excitons, a new class of quantum particles, that were only theoretically known to exist so far.
Category: particle physics – Page 69
Antiprotons from Beyond the Solar System
The spectrum of cosmic-ray antiprotons has been measured for a full solar cycle, which may allow a better understanding of the sources and transport mechanisms of these high-energy particles.
The heliosphere is a region of space extending approximately 122 astronomical units (au) from the Sun (1 au being the average distance between the Sun and Earth). This volume mostly contains plasma originating from the Sun but also various charged particles with higher energies. These particles can be categorized according to their energies and origins: Lower-energy solar energetic particles, for instance, come from the Sun itself, while Jovian electrons have their origin in the magnetosphere of Jupiter. Another such population comes from outside the Solar System: galactic cosmic rays (GCRs), which mostly consist of protons and electrons and their antiparticles and span a vast range of energies from mega-electron-volts to exa-electron-volts [1]. Astonishingly, energies at the high end of this range would correspond to a single particle carrying as much kinetic energy as a well-thrown baseball.
Language models can improve physics measurements with improved tau reconstruction
In order to find rare processes from collider data, scientists use computer algorithms to determine the type and properties of particles based on the faint signals that they leave in the detector. One such particle is the tau lepton, which is produced, for example, in the decay of the Higgs boson.
The tau lepton leaves a spray or jet of low-energy particles, the subtle pattern of which in the jet allows one to distinguish them from jets produced by other particles. The jet also contains information about the energy of the tau lepton, which is distributed among the daughter particles, and on the way is decayed. Currently, the best algorithms use multiple steps of combinatorics and computer vision.
ChatGPT has shown much stronger performance in rejecting backgrounds than computer-vision based methods. In this paper, researchers showed that such language-based models can find the tau leptons from the jet patterns, and also determine the energy and decay properties more accurately than before.
A high-temperature multiferroic Tb2(MoO4)3
The mutual control of magnetization and polarization in multiferroics is key to spintronic devices, but ensuring its stability at room temperature is essential for practical applications. Here, magnetic control of ferroelectric polarization in Tb2(MoO4)3 is demonstrated up to 432 K, ensuring the stability of magnetoelectric effect well above room temperature.
Physicists decipher structure of antimony melt, explain nature of observed structural anomalies
Antimony is widely used in the production of materials for electronics, as well as metal alloys resistant to corrosion and high temperatures.
“Antimony melt is interesting because near the melting point, the atoms in this melt can form bound structures in the form of compact clusters or extended chains and remain in a bound state for quite a long time. We found out that the basic unit of these structures are linked triplets of adjacent atoms, and the centers of mass of these linked atoms are located at the vertices of right triangles. It is from these triplets that larger structures are formed, the presence of which causes anomalous structural features detected in neutron and X-ray diffraction experiments,” explains Dr. Anatolii Mokshin, study supervisor and Chair of the Department of Computational Physics and Modeling of Physical Processes.
The computer modeling method based on quantum-chemical calculations made it possible to reproduce anomalies in the structure of molten antimony with high accuracy.
Unlocking Quantum Mysteries: New Device Bridges Classical and Quantum Physics
In a groundbreaking study published in the journal Optica, this innovative instrument emerges from the collaborative genius of the National Quantum Science and Technology Institute (NQSTI), incorporating expertise from several esteemed institutions. The device serves as a window into a dual universe, allowing the simultaneous examination of phenomena governed by both classical laws and the bizarre rules of quantum mechanics.
At the heart of this discovery lies the technique of optical trapping, a method that harnesses the power of light to manipulate microscopic particles. Now, empowered by the insights of physicist Francesco Marin and his team, the dual laser setup dramatically enhances our understanding of how these nano-objects interact. As they oscillate in their laser confines, the spheres reveal a dance of behaviors—some that align with our everyday experiences, and others that defy our intuition.
Scientists find more microplastics in human brains than in kidneys and livers—and levels are rising
Tiny plastic particles may accumulate at higher levels in the human brain than in the kidney and liver, with greater concentrations detected in postmortem samples from 2024 than in those from 2016, suggests a paper published in Nature Medicine. Although the potential implications for human health remain unclear, these findings may highlight a consequence of rising global concentrations of environmental plastics.
The amount of environmental plastic nano-and microparticles, which range in size from as small as 1 nanometer (one billionth of a meter) up to 500 micrometers (one millionth of a meter) in diameter, has increased exponentially over the past 50 years. However, whether they are harmful or toxic to humans is unclear. Most previous studies used visual microscopic spectroscopy methods to identify particulates in human tissues, but this is often limited to particulates larger than 5 micrometers.
Researcher Matthew Campen and colleagues used novel methods to analyze the distribution of micro-and nanoparticles in samples of liver, kidney, and brain tissues from human bodies that underwent autopsy in 2016 and 2024. A total of 52 brain specimens (28 in 2016 and 24 in 2024) were analyzed.
Quantum Systems Obey Second Law Of Thermodynamics
The fundamental principles of thermodynamics have long been a cornerstone of our understanding of the physical world, with the second law of thermodynamics standing as a testament to the inexorable march towards disorder and entropy that governs all closed systems. However, the realm of quantum physics has traditionally appeared to defy this notion, with mathematical formulations suggesting that entropy remains constant in these systems.
Recent research has shed new light on this seeming paradox, revealing that the apparent contradiction between quantum mechanics and thermodynamics can be reconciled through a nuanced understanding of entropy itself. By adopting a definition of entropy that is compatible with the principles of quantum physics, specifically the concept of Shannon entropy, scientists have demonstrated that even isolated quantum systems will indeed evolve towards greater disorder over time, their entropy increasing as the uncertainty of measurement outcomes grows.
This breakthrough insight has far-reaching implications for our comprehension of the interplay between quantum theory and thermodynamics, and is poised to play a pivotal role in the development of novel quantum technologies that rely on the manipulation of complex many-particle systems.
Physicists Confirm The Existence of a Third Form of Magnetism
An experiment in Sweden has demonstrated control over a novel kind of magnetism, giving scientists a new way to explore a phenomenon with huge potential to improve electronics – from memory storage to energy efficiency.
Using a device that accelerates electrons to blinding speeds, a team led by researchers from the University of Nottingham showered an ultra-thin wafer of manganese telluride with X-rays of different polarizations, to reveal changes on a nanometer scale reflecting magnetic activity unlike anything seen before.
For a rather mundane chunk of iron to transform into something a little more magnetic, its constituent particles need to be arranged so that their unpartnered electrons align according to a property known as spin.