750-TeV IceCube alert led astronomers to a rare, lensed dusty starburst at redshift 2.988. The galaxy is the best candidate in the field, not a confirmed neutrino source.
Category: particle physics – Page 18
With a feel for physics, AI models simulate a wider range of real-world scenarios
Artificial intelligence models are jacks of many trades, including writing, generating images, and creating 3D models. But they aren’t as helpful when it comes to testing robots or designs for vehicles in diverse environments, since they don’t understand physics as well as they do pixels or text.
To build an AI system that can reliably simulate a variety of physical scenarios, engineers need physics data at a scale that is not yet feasible. That’s because it is very time-consuming to generate even a few data points that neural networks can understand. They rely on algorithms called “numerical solvers” to calculate physical properties at different points of a 3D shape. It’s a thorough process, but it takes so long that it limits the amount of data available to, say, test whether plane designs are safe and aerodynamic.
A new pretraining approach known as “GeoPT,” developed by researchers at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) and Tsinghua University, gives simulation models a chance to learn physics in a broader, more efficient way. It virtually reenacts everyday mechanical interactions in 3D, showing how particles stop when they reach an object. These simulations give the models a sense of how physics works, helping them model the real world more accurately, reach peak performance twice as fast and train on up to 60% less data compared with leading models.
Oxygen vacancies unlock fast lithium-ion transport in battery material
Lithium titanate (LTO, Li4Ti5O12) is a well-established battery material that in its pristine state is a poor conductor of lithium ions. It develops high ionic conductivity only during charging, when additional lithium ions and electrons are incorporated into the material.
Bernhard Gadermaier and Martin Wilkening from the Institute of Chemistry and Technology of Materials at TU Graz have taken an entirely different approach: They transformed pure, non-lithiated LTO in its original composition, Li4Ti5O12, into a significantly better ion conductor by deliberately introducing defects into the crystal lattice.
Specifically, they removed individual oxygen atoms, thereby creating oxygen vacancies that activate a previously blocked migration pathway for lithium ions. “This diffusion pathway is already pre-formed in the LTO structure but is only activated by the defect structure,” Wilkening explains.
Copper’s surprising melting behavior provides insights into future fusion design
Future fusion power plants aim to recreate the heart of a star here on Earth to power our future energy needs. While the core fusion plasma will burn at hundreds of millions of degrees, the surrounding structural components must handle sudden, punishing heat loads that rival the extreme temperatures faced by spacecraft upon reentry into Earth’s atmosphere. Copper and its alloys are primary candidates for handling these intense heat fluctuations, making it vital to understand exactly how the metal behaves when pushed to its melting point.
Now, researchers at the Department of Energy’s SLAC National Accelerator Laboratory and collaborators have captured a detailed, step-by-step look at copper atoms as they underwent extreme heating. Published in Nature Communications, the results revealed a key parameter that allowed copper’s crystal lattice to melt steadily rather than collapse instantaneously, as earlier simulations predicted.
“These results greatly improve the simulations we use to predict which materials have the best shot at surviving the extreme conditions of future fusion reaction chambers,” said Mianzhen Mo, a SLAC staff scientist who led the research. “They also demonstrate the incredible, atomic-scale resolution imaging we can achieve at SLAC’s electron camera.”
X-ray analysis reveals the inner life of leaves while advancing engineering efforts to reduce ‘crop sweat’
In the Midwestern summer, humans and plants have to breathe through the heat and humidity. Researchers hope that a retooled crop plant—one with an improved ventilation system within its leaves—could thrive while avoiding drought stress by reducing “crop sweat.” Thanks to next-generation imaging technology powered by Argonne National Laboratory’s particle collider beamline, a team of scientists now has precise schematics of the leaf’s interior and can refine approaches to breeding hardier crop plants.
The research, published in Plant Physiology, was led by postdoctoral researcher James Fischer in the laboratory of plant biology and crop sciences professor Andrew Leakey at the University of Illinois Urbana-Champaign. Their work represents the first detailed look at how the pores on the leaf surfaces of sorghum, a highly productive and resilient grass crop, connect to the air pathways, photosynthetic centers and veins beneath.
“There are connections between each component of the leaf… t’s a highly organized system,” Fischer said. “We are really defining the leaf beyond just carbon dioxide goes in, water comes out.”
LHC collisions reveal oxygen and neon’s shifting nuclear geometry
Many people are aware that the Large Hadron Collider (LHC) at CERN smashes tiny subatomic particles together at nearly the speed of light to test foundational laws of physics and discover new fundamental particles, but some experiments also help scientists better visualize the actual structure of atoms we are already familiar with, like oxygen and neon.
While science textbooks often feature pictures of these and other atoms as if their nuclei are well-defined structures, the reality is more complicated. A new study, published in Physical Review Letters, reveals new details about the internal structure of oxygen and neon from the flow of particles coming out of oxygen-oxygen and neon-neon collisions in the LHC.
A little Big Bang: Bowling-pin-shaped nuclei shed new light on the universe’s first moments
What happened in the first moments of the universe—before the building blocks of life and the world we know today came into existence? Physicists at the CERN research facility in Switzerland are trying to answer this question by recreating some of the extreme conditions that prevailed in the universe during its earliest history. Now, researchers from the Niels Bohr Institute, together with colleagues from the international ALICE collaboration, have come one step closer to understanding those conditions.
At CERN, researchers can make atomic nuclei collide at almost the speed of light, creating tiny droplets of the primordial matter that filled the universe during its first millionth of a second. This matter is known as quark-gluon plasma and is thought to have been the earliest form of matter in the universe.
For many years, scientists have assumed that creating this plasma required collisions between very heavy atomic nuclei such as lead. But physicists from the Niels Bohr Institute have now succeeded in creating the primordial matter by smashing the much smaller nuclei of oxygen-16 and neon-20 together.
Magnetically levitated quantum bit could address design flaws
Researchers at the FAMU-FSU College of Engineering and the National High Magnetic Field Laboratory, headquartered at Florida State University, have designed a new quantum computing architecture that uses magnetic levitation to smooth over design flaws in the intricate components necessary to run a quantum computer.
Quantum bits, or qubits, can be as small as a few nanometers, and manufacturing them inevitably introduces random flaws on their surfaces. By using superconducting magnets to levitate neon particles, the research addresses a challenge in electron-on-neon qubit devices: the tendency for electrons to become trapped by tiny random bumps on the neon surface, making them function unpredictably.
The study, published in PRX Quantum, could help pave the way for more reproducible and scalable quantum computing technologies.
AI boosts sensitivity to double-Higgs signatures occurring about once per trillion collisions
Is the universe as stable as we think it is? That’s one of the big questions that particle physicists worldwide are preparing to answer with the Large Hadron Collider, or LHC—the world’s most powerful particle accelerator—when its upgrade is completed in about four years. In the meantime, researchers, including a cohort at the University of Michigan, are working to sharpen their analytical tools and techniques to make the most of the LHC’s current and future data.
A team including U-M physicists has now reported record-setting sensitivity in spotting a specific interaction within the LHC’s data that may help answer fundamental questions about our universe. In particular, the analysis uses an advanced AI algorithm to spot signatures researchers are looking for to understand how the Higgs boson, the famous fundamental particle that helps explain how subatomic particles have mass, interacts with itself.
“This analysis is the most sensitive in the world to this specific physics,” said Greg Myers, a research fellow in the U-M Department of Physics.