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Category: particle physics – Page 57

Dark Matter’s Secret: A Daring Experiment Seeks the Elusive Axion

Scientists are hunting for axions, tiny particles that could solve major physics mysteries, including why neutrons don’t have an electric dipole moment and what dark matter is made of. Using the powerful European XFEL in Hamburg, researchers fired X-rays through special crystals, hoping to witness axions converting into light—a sign of their existence. This pioneering experiment, already competitive with major particle accelerator studies, demonstrates that XFEL technology could be a game-changer in particle physics.

First dark matter search using WINERED spectrograph sets new lifetime constraints

Dark matter is an elusive type of matter that does not emit, absorb or reflect light and is thus impossible to detect using conventional techniques employed in particle physics. In recent years, groups of physicists worldwide have been trying to observe this matter indirectly using advanced detectors and equipment, by detecting signals other than electromagnetic radiation that could be linked to its activity or interactions with other matter.

Researchers at Tokyo Metropolitan University, PhotoCross Co. Ltd, Kyoto Sangyo University and other collaborating institutions recently released the findings of the first search for dark matter that relied on data collected by WINERED, a near-infrared and high-dispersion spectrograph mounted on a in Chile.

Their paper, published in Physical Review Letters, sets the most stringent constraints to date on the lifetime of dark matter particles with masses between 1.8 and 2.7 eV.

Research illuminates the path to superior electro-optic performance in aluminum scandium nitride alloys

From integrated photonics to quantum information science, the ability to control light with electric fields—a phenomenon known as the electro-optic effect—supports vital applications such as light modulation and frequency transduction. These components rely on nonlinear optical materials, in which light waves can be manipulated by applying electric fields.

Conventional nonlinear optical materials such as lithium niobate have a large electro-optic response but are hard to integrate with silicon devices. In the search for silicon-compatible materials, aluminum scandium nitride (AlScN), which had already been flagged as an excellent piezoelectric—referring to a material’s ability to generate electricity when pressure is applied, or to deform when an electric field is applied—has come to the fore. However, better control of its properties and means to enhance its electro-optic coefficients are still required.

Researchers in Chris Van de Walle’s computational materials group at UC Santa Barbara have now uncovered ways to achieve these goals. Their study, published in Applied Physics Letters, explains how adjusting the material’s atomic structure and composition can boost its performance. Strong electro-optic response requires a large concentration of scandium—but the specific arrangement of the scandium atoms within the AlN crystal lattice matters.

Green process converts almost any carbon source into graphene

RESEARCHERS at Rice University, US have discovered a green process which can quickly and cheaply produce graphene from almost any carbon source, including coal, mixed plastic waste, biomass, and waste food. It could facilitate a reduction in the environmental impact of concrete and other building materials.

Graphene is the strongest known material. It is comprised of a single layer of carbon atoms arranged in a two-dimensional hexagonal lattice, in which one atom forms each vertex. A tiny amount of graphene can significantly enhance the properties of materials such as plastics, paints, composites, wood composites, concrete, metals, and lubricant. However, it is expensive to manufacture, so has limited industrial applications.

The process discovered at Rice employs flash Joule heating is a process where an electric current is passed through a conductor to produce heat. Using a custom reactor, the Rice researchers can produce graphene in 10 ms. The carbon source is placed between two electrodes and 200 V is applied in a short electrical pulse, heating the material to more than 3,000K (2726.9°C). Non-carbon elements sublime and the remaining carbon atoms reconstruct into carbon.

Physicists Discover a Magnetic Breakthrough That Could Supercharge Quantum Tech

Scientists have found a new way to control quantum information using a special material, chromium sulfide bromide.

It can store and process data in multiple forms, but its magnetic properties are the real game-changer. By adjusting its magnetization, researchers can confine excitons—quantum particles that carry information—allowing for longer-lasting quantum states and new ways to process data.

Quantum “Miracle Material” Enables Magnetic Switching.

Magnetic ‘invisibility cloak’ hides obstacles within particle streams

Researchers at the University of Bayreuth have developed a method that makes objects on a magnetic field invisible within a particle stream. Until now, this so-called cloaking had only been studied for waves such as light or sound. They report their results in Nature Communications.

Making objects invisible is no longer a purely fictional idea from fantasy or sci-fi films. At least to some extent, cloaking also works in research: manipulating objects in such a way that they become invisible to certain waves such as light or sound.

The Bayreuth researchers are extending cloaking to particle motions. Cloaking for particle streams on miniaturized chemical laboratories, so-called lab-on-a-chip devices, can help to transport active ingredients in a targeted manner without exposing them to undesirable premature chemical reactions.

High-speed videos show what happens when a droplet splashes into a pool

Rain can freefall at speeds of up to 25 miles per hour. If the droplets land in a puddle or pond, they can form a crown-like splash that, with enough force, can dislodge any surface particles and launch them into the air.

Now MIT scientists have taken high-speed videos of droplets splashing into a deep pool, to track how the fluid evolves, above and below the water line, frame by millisecond frame. Their work could help to predict how spashing droplets, such as from rainstorms and irrigation systems, may impact watery surfaces and aerosolize surface particles, such as pollen on puddles or pesticides in agricultural runoff.

The team carried out experiments in which they dispensed water droplets of various sizes and from various heights into a pool of water. Using high-speed imaging, they measured how the liquid pool deformed as the impacting droplet hit the pool’s surface.

Hypercharge breaking scenarios could explain the baryon asymmetry of the universe

The Standard Model ℠, the main physics framework describing elementary particles and the forces driving them, outlines key patterns in physical interactions referred to as gauge symmetries. One of the symmetries it describes is the so-called UY hypercharge: a gauge symmetry that contributes to the electric charge of particles before electromagnetic and weak forces become distinct (i.e., before the electroweak phase transition).

Researchers at Universidad Autónoma de Madrid’s Theoretical Physics Department (DFT) and Instituto de Física Teórica (IFT) recently carried out a study investigating how the conditions present in the early universe could prompt the spontaneous breaking of this gauge symmetry, linking this phenomenon to certain models of neutrino mass generation known as radiative neutrino mass models. Their paper, published in Physical Review Letters, specifically builds on a theoretical framework called the Zee-Babu model, an extension of the SM explaining neutrino mass generation.

“In the SM, the spontaneously broken electroweak gauge symmetry, which governs the electromagnetic and weak interactions of nature, was restored in the universe’s first instants, when the universe’s temperature was higher than the electroweak energy scale,” Prof. Jose Miguel No, Luca Merlo, Alvaro Lozano-Onrubia and Sergio López-Zurdo told Phys.org.

New calculation links disparate pion reactions in nuclear physics

An early-career physicist mathematically connects timelike and spacelike form factors, opening the door to further insights into the inner workings of the strong force. A new lattice QCD calculation connects two seemingly disparate reactions involving the pion, the lightest particle governed by the strong interaction.

As an undergraduate student at Tecnológico de Monterrey in Mexico, Felipe Ortega-Gama worked at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility as part of the Science Undergraduate Laboratory Internships program. There, Ortega-Gama worked with Raúl Briceño, who was a jointly appointed staff scientist in the lab’s Center for Theoretical and Computational Physics (Theory Center) and professor at Old Dominion University.

Briceño introduced him to quantum chromodynamics (QCD), the theory that describes the strong interaction. This is the force that binds quarks and gluons together to form protons, neutrons and other particles generically called hadrons. Theorists use lattice QCD, a computational method for solving QCD, to make predictions based on this theory. These predictions are then used to help interpret the results of experiments involving hadrons.

AI designs an ultralight carbon nanomaterial that’s as strong as steel

Using machine learning, a team of researchers in Canada has created ultrahigh-strength carbon nanolattices, resulting in a material that’s as strong as carbon steel, but only as dense as Styrofoam.

The team noted last month that it was the first time this branch of AI had been used to optimize nano-architected materials. University of Toronto’s Peter Serles, one of the authors of the paper describing this work in Advanced Materials, praised the approach, saying, “It didn’t just replicate successful geometries from the training data; it learned from what changes to the shapes worked and what didn’t, enabling it to predict entirely new lattice geometries.”

To quickly recap, nanomaterials are engineered by arranging atoms or molecules in precise patterns, much like constructing structures with extremely tiny LEGO blocks. These materials often exhibit unique properties due to their nanoscale dimensions.