A disagreement over neutrino-mass estimates might be resolved by assuming that neutrinos decay into hypothetical massless particles.
Category: particle physics
Electron matter waves gain ultrafast torque that flips handedness in femtoseconds
Many natural processes, ranging from magnetism to chemical reactions, entail the movement and rotation of particles at very small scales. In quantum mechanics, particles exhibit both particle-like and wave-like behaviors, and their states can be described mathematically using representations known as wavefunctions.
The reliable manipulation of wave-like properties of particles as small as atoms or single electrons could open new possibilities both for studying matter and for engineering materials with desirable characteristics. Notably, controlling the angular momentum, which is the quantum property related to rotational motion, of ultrasmall particles at ultrafast timescales has so far proved very challenging when only using conventional, laser-based approaches.
Researchers at Universität Konstanz recently devised a new approach to create electron beams with an ultrafast internal torque (i.e., twisting motion). Their proposed strategy, outlined in a paper published in Nature Physics, could be a promising tool for exploring material dynamics and quantum phenomena at atomic and subatomic scales.
Diffusion model links foam physics to voting shifts and market behavior
A drop of dye added to a glass of water undergoes ordinary diffusion. However, when placed on the surface of a foam, the dye spreads differently—diffusion becomes anomalous. An example of this is the pattern on the froth of a cup of cappuccino. Interestingly, recent research suggests that diffusion equations in a heterogeneous environment can also describe social phenomena, such as election results or the behavior of stock market traders. The study is published in the Chaos: An Interdisciplinary Journal of Nonlinear Science.
The movement of particles in complex media—such as porous materials, gels or foams—bears more resemblance to a random journey through an irregular maze than to a leisurely stroll through a homogeneous space. The presence of local “traps” alongside narrow passages or branches causes the transport of matter or energy to be significantly slowed down or accelerated. Such deviations from classical diffusion are referred to as anomalous diffusion. It is also observed in media with a nonuniform structure.
An international team of physicists from Poland, Croatia, Macedonia and Hungary has undertaken a mathematical description of diffusion in such systems; the Polish side was represented by scientists from the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Cracow.
From Supernova Physics to Fusion Energy: The Laser Experiments Changing Science — Dr. Mario Manuel
Fusion energy is no longer just science fiction — it’s becoming experimental reality. Dr. Mario Manuel, Ph.D. — General Atomics.
What if we could recreate the inside of a star — not in theory, but inside a laboratory on Earth using the world’s most powerful lasers?
Dr. Mario Manuel, Ph.D. is a plasma physicist and laser-science researcher at whose work sits at the frontier of fusion energy, laboratory astrophysics, high-energy-density physics, and advanced laser diagnostics. Trained in applied plasma physics and aerospace engineering, Dr. Manuel has spent his career developing new ways to visualize and understand the extreme electromagnetic environments created when ultra-powerful lasers interact with matter.
Dr. Manuel’s research has spanned some of the most ambitious scientific efforts underway today — from inertial fusion energy and plasma-instability control to recreating supernova-like shock waves in the laboratory and generating ultra-intense gamma-ray and particle beams using petawatt-class lasers.
Early in his career, Dr. Manuel helped pioneer advanced proton-radiography techniques capable of imaging invisible electric and magnetic fields inside laser-produced plasmas, work that opened new windows into the turbulent physics that can either enable or destroy fusion reactions.
Scientists think they solved the mystery of the Amaterasu particle
The mysterious Amaterasu particle may not be a proton at all. New research suggests that some of the most extreme cosmic rays could be ultraheavy atomic nuclei, heavier than iron, which are better able to retain their energy while traveling through space. This idea could help explain how these rare particles reach Earth and provide new clues about the powerful cosmic explosions that create them.
Collapsing stars could spawn mini-universes, offering new path to gravastars
Stars shine because atoms fuse in their interiors, releasing energy. When a very massive star has exhausted its nuclear fuel, radiation pressure can no longer provide sufficient counterforce to gravity. The star then collapses under its own mass until only a single point remains: the singularity.
While the formation of a black hole appears plausible, black holes themselves continue to pose major challenges for science. How can 10 billion solar masses concentrate at a single tiny point? How can spacetime be curved infinitely at that point, the singularity? At this stage, the laws of physics break down, making it impossible to predict what happens. Moreover, black holes conceal all information from observation: Everything, including light, disappears irretrievably beyond the event horizon.
Does the Universe Contain Negative-Mass Particles?
The mainstream of cosmology asserts that 84% of the matter in the Universe is invisible, labeled as “dark matter”. The total matter which accounts for attractive gravity amounts to 32% of the cosmic mass-energy budget, while the remaining 68% — in the form of “dark energy”- induces repulsive gravity. The ordinary matter that we are made of, makes only 5% of the cosmic budget. We are made of rare materials in the cosmic context!
Since the dark matter and dark energy components are invisible, we had not observed them directly but only inferred them indirectly through their gravitational influence. This is all fine as long as gravity is the curvature of spacetime, as formulated by Albert Einstein in 1916. Despite the overwhelming consensus of the mainstream, the nature of dark matter and dark energy remains unknown following a century of unsuccessful searches. Is it possible that these constituents are fictitious “ghosts” that do not actually exist, but were imagined because Einstein’s equations fail to describe gravity correctly on cosmic scales?
I spent the day today brainstorming through this possibility along the following lines.
AI helps reveal large-scale quantum effects hidden in stacked atomic sheets
Quantum materials are a class of exotic materials with special properties that are governed by quantum mechanics rather than classical physics. Those properties—like superconductivity, entanglement and unusual forms of magnetism—often originate in the tiny repeating patterns of atoms inside crystals, but through clever engineering, they can be observed and controlled at a more human scale. Quantum materials are helping to power the quickly growing field of quantum computing and could find their way into future generations of energy-efficient electronics.
Designing new materials from the atomic scale up, however, requires intense modeling and simulation. Some materials may appear ordinary when viewed as small clusters of atoms, yet reveal new and useful properties when their atomic building blocks repeat and interact over larger distances. Researchers must be able to accurately predict behaviors at large scales in order to find materials with practical applications—otherwise, designing new materials is a slow and costly trial-and-error process.
In the past 50 years, supercomputers have helped materials scientists solve some of those thorny prediction problems, but two recent studies from the University of Washington demonstrate how newer computing techniques can help researchers sniff out promising quantum materials to pursue.
An underground detector in China unveils its first major findings about mysterious ghost particles
A massive underground detector aimed at understanding the mysterious ghost particles in our universe released its first major results on Wednesday.
The Jiangmen Underground Neutrino Observatory in China started collecting data in August with the goal of understanding neutrinos: tiny cosmic particles that date back to the Big Bang and whiz harmlessly through our bodies by the trillions every second. Yet they weigh almost nothing, making them difficult to sniff out.
In a study published Wednesday in the journal Nature, the JUNO team unveiled its initial findings from two months of data collection—including some of the most precise measurements to date of how neutrinos switch between three varieties, or flavors, as they zip through space.
Quantum witness technique reveals spinons in quantum spin liquid candidate
Physicists at University College Cork have developed a new approach in the search for a quantum spin liquid, a long-sought state of quantum matter resembling a magnetic liquid whose quantum properties mean it never freezes. The work is a key step in the search for quantum silicon, a mineral that could be used to create quantum computers, just as silicon is used in traditional computers. The resulting paper appears in Nature Physics.
Lead author Prof. Seamus Davis said, “By introducing the quantum witness technique we provide a completely new perspective on the physics of quantum spin liquids and access their internal quantum excitations or ‘spinons’ directly for the first time at UCC.”
As liquids cool, they freeze into solids as their atoms cease to move. But some liquids, such as helium, never freeze. Predominant quantum effects mean they flow as superfluids even at absolute zero (the coldest possible temperature).