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Archive for the ‘particle physics’ category: Page 131

Jan 11, 2023

Explaining Anomalies in Reactor Antineutrinos

Posted by in categories: nuclear energy, particle physics

Several experiments have been set up outside nuclear reactors to record escaping antineutrinos. The data generally agrees with theory, but at certain energies, the antineutrino flux is 6–10% above or below predictions. These so-called reactor antineutrino anomalies have excited the neutrino community, as they could be signatures of a hypothetical sterile neutrino (see Viewpoint: Getting to the Bottom of an Antineutrino Anomaly). But a new analysis by Alain Letourneau from the French Atomic Energy Commission (CEA-Saclay) and colleagues has shown that the discrepancies may come from experimental biases in associated electron measurements [1].

The source of reactor antineutrinos is beta decay, which occurs in a wide variety of nuclei (more than 800 species in a typical fission reactor). To predict the antineutrino flux, researchers have typically used previously recorded data on electrons, which are also produced in the same beta decays. This traditional method takes the observed electron spectra from nuclei, such as uranium-235 and plutonium-239, and converts them into predicted antineutrino spectra. But Letourneau and colleagues have found reason to doubt the electron measurements.

The team calculated antineutrino spectra—as well as the corresponding electron spectra—using a fundamental theory of beta decay. This method works for some nuclei, but not all, so the researchers plugged the gaps using a phenomenological model. They were able to treat all 800-plus reactor beta decays, finding “bumps” in the antineutrino flux that agree with observations. Similar features are predicted for electron spectra, but they don’t show up in the data. The results suggest that an experimental bias in electron observations causes the reactor antineutrino anomalies. To confirm this hypothesis, the researchers call for new precision measurements of the fission electrons.

Jan 11, 2023

The Sounds of Atoms

Posted by in category: particle physics

Transforming the spectral lines of each element into a musical tone provides a fun tool for teasing out patterns in the electronic structures of atoms.

Jan 9, 2023

By Producing Two Entangled Beams of Light, Researchers Have Achieved a Breakthrough in Quantum Physics

Posted by in categories: particle physics, quantum physics

Researchers in Brazil have achieved a quantum breakthrough by succeeding in the creation of a source of illumination that produces two separate entangled beams of light, according to new research.

The achievement was announced by a team of physicists with Brazil’s Laboratory for Coherent Manipulation of Atoms and Light (LMCAL), located at the University of São Paulo’s Physics Institute.

Quantum entanglement is among the most perplexing phenomena observed in modern physics. It involves particles that are linked in such a way that when changes affect the quantum state of one, the other to which it is “entangled” will also be affected. Strangely, such effects even occur over significant distances, a phenomenon first described as “spooky action at a distance” after its discussion in a landmark 1935 paper by Albert Einstein, Boris Podolsky, and Nathan Rosen.

Jan 9, 2023

Two Light-Trapping Techniques Combine for the Best of Both Worlds

Posted by in categories: particle physics, quantum physics, robotics/AI

Taming rays of light and bending them to your will is tricky business. Light travels fast and getting a good chunk of it to stay in one place for a long time requires a lot of skillful coaxing. But the benefits of learning how to hold a moonbeam (or, more likely, a laser beam) in your hand, or on a convenient chip, are enormous. Trapping and controlling light on a chip can enable better lasers, sensors that help self-driving cars “see,” the creation of quantum-entangled pairs of photons that can be used for secure communication, and fundamental studies of the basic interactions between light and atoms—just to name a few.

Of all the moonbeam-holding chip technologies out there, two stand the tallest: the evocatively named whispering gallery mode microrings, which are easy to manufacture and can trap light of many colors very efficiently, and photonic crystals, which are much trickier to make and inject light into but are unrivaled in their ability to confine light of a particular color into a tiny space—resulting in a very large intensity of light for each confined photon.

Recently, a team of researchers at JQI struck upon a clever way to combine whispering gallery modes and photonic crystals in one easily manufacturable device. This hybrid device, which they call a microgear photonic crystal ring, can trap many colors of light while also capturing particular colors in tightly confined, high-intensity bundles. This unique combination of features opens a route to new applications, as well as exciting possibilities for manipulating light in novel ways for basic research.

Jan 9, 2023

Nanoplastics unexpectedly produce reactive oxidizing species when exposed to light

Posted by in categories: chemistry, engineering, particle physics

Plastics are ubiquitous in our society, found in packaging and bottles as well as making up more than 18% of solid waste in landfills. Many of these plastics also make their way into the oceans, where they take up to hundreds of years to break down into pieces that can harm wildlife and the aquatic ecosystem.

A team of researchers, led by Young-Shin Jun, Professor of Energy, Environmental & Chemical Engineering in the McKelvey School of Engineering at Washington University in St. Louis, analyzed how light breaks down polystyrene, a nonbiodegradable plastic from which packing peanuts, DVD cases and disposable utensils are made. In addition, they found that nanoplastic particles can play active roles in environmental systems. In particular, when exposed to light, the nanoplastics derived from polystyrene unexpectedly facilitated the oxidation of aqueous ions and the formation of manganese oxide solids that can affect the fate and transport of organic contaminants in natural and engineering water systems.

The research, published in ACS Nano on Dec. 27, 2022, showed how the photochemical reaction of nanoplastics through light absorption generates peroxyl and superoxide radicals on surfaces, and initiates oxidation of manganese into manganese oxide solids.

Jan 8, 2023

Physicists just discovered a new type of quantum entanglement

Posted by in categories: computing, particle physics, quantum physics

For the first time, physicists at the Brookhaven National Laboratory have come across a novel type of quantum entanglement, the extremely bizarre phenomenon that occurs when a pair of particles remain connected even when separated by galactic distances. Thanks to this effect, the researchers were also able to peer inside the atomic nuclei with unprecedented detail.

Quantum entanglement is a strange and fascinating phenomenon that has puzzled scientists for decades. It occurs when pairs of particles become so closely connected that one can no longer be described without the other, no matter how far apart they may be. Even more strange, changing one will instantly trigger a change in its partner, even if it was on the other side of the universe. In theory, this effect would enable faster-than-light communication if you encode the changes in these states with 1s and 0s.

This concept may sound impossible to us, as it goes against our classical understanding of physics, and it even unnerved Albert Einstein, who referred to it as “spooky action at a distance.” However, numerous experiments have consistently proven the existence of quantum entanglement by manipulating the properties of the entangled particles, such as their spin or polarization, and observing the effects on the other particle. Today, quantum entanglement forms the backbone of emerging technologies such as quantum computers and networks.

Jan 8, 2023

New measurements support the idea that dark matter doesn’t exist

Posted by in categories: cosmology, particle physics

Despite numerous searches, we have yet to detect dark matter particles.

Jan 8, 2023

How these factors could lead to better nanomedicine treatments

Posted by in categories: biological, biotech/medical, particle physics

Better treatments are definitely on the way.

Nanomedicines took the spotlight during the COVID-19 pandemic. Researchers are using these very small and intricate materials to develop diagnostic tests and treatments. Nanomedicine is already used for various diseases, such as the COVID-19 vaccines and therapies for cardiovascular disease. The “nano” refers to the use of particles that are only a few hundred nanometers in size, which is significantly smaller than the width of a human hair.


NIH Image Gallery/Flickr.

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Jan 7, 2023

Physicists confirm effective wave growth theory in space

Posted by in categories: particle physics, satellites

A team from Nagoya University in Japan has observed, for the first time, the energy transferring from resonant electrons to whistler-mode waves in space. Their findings offer direct evidence of previously theorized efficient growth, as predicted by the non-linear growth theory of waves. This should improve our understanding of not only space plasma physics but also space weather, a phenomenon that affects satellites.

When people imagine , they often envision it as a perfect vacuum. In fact, this impression is wrong because the vacuum is filled with charged particles. In the depths of space, the density of charged particles becomes so low that they rarely collide with each other.

Instead of collisions, the forces related to the electric and magnetic fields filling space, control the motion of charged particles. This lack of collisions occurs throughout space, except for very near to celestial objects, such as stars, moons, or planets. In these cases, the charged particles are no longer traveling through the vacuum of space but instead through a medium where they can strike other particles.

Jan 7, 2023

First Quantum Entanglement Between Dissimilar Particles Provides A View Inside Atomic Nuclei

Posted by in categories: particle physics, quantum physics

Positively and negatively charged versions of the same particle have been entangled for the first time, allowing us to map the hearts of atoms more precisely and opening the doors to more powerful communication tools.

The neutrons and protons that make up the nuclei of atoms are, in turn, composed of quarks. However, quarks alone would be unstable; they need gluons, the carriers of the strong force, to hold them together. Gluons are orders of magnitude too small to see, even with the most powerful microscopes – but they can still interact with photons to produce exceptionally short-lived rho particles that decay to charged two-quark particles called pions.

By measuring the angles and speed at which the positive and negative pions (π+ and π-) emerge, scientists at the Brookhaven National Laboratory have created a map of gluon distribution within the nuclei of gold and uranium atoms. They report this map to be the most precise description of the inner workings of an atomic nucleus.