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Archive for the ‘particle physics’ category: Page 364

Dec 28, 2020

Searching for invisible axion dark matter with a new multiple-cell cavity haloscope

Posted by in categories: cosmology, particle physics

Over the past few decades, many experimental physicists have been probing the existence of particles called axions, which would result from a specific mechanism that they think could explain the contradiction between theories and experiments describing a fundamental symmetry. This symmetry is associated with a matter-antimatter imbalance in the Universe, reflected in interactions between different particles.

If this mechanism took place in the early Universe, such a particle might have a very small mass and be ‘invisible. Subsequently, researchers proposed that the might also be a promising candidate for dark matter, an elusive, hypothetical type of matter that does not emit, reflect or absorb light.

While dark matter has not yet been experimentally observed, it is believed to make up 85% of universe’s mass. Detecting axions could have important implications for ongoing dark matter experiments, as it could enhance the present understanding of these elusive particles.

Dec 28, 2020

Repulsive gravity as an alternative to dark energy (Part 2: In the quantum vacuum)

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

Circa 2012


(PhysOrg.com) — During the past few years, CERN physicist Dragan Hajdukovic has been investigating what he thinks may be a widely overlooked part of the cosmos: the quantum vacuum. He suggests that the quantum vacuum has a gravitational charge stemming from the gravitational repulsion of virtual particles and antiparticles. Previously, he has theoretically shown that this repulsive gravity can explain several observations, including effects usually attributed to dark matter. Additionally, this additional gravity suggests that we live in a cyclic Universe (with no Big Bang) and may provide insight into the nature of black holes and an estimate of the neutrino mass. In his most recent paper, published in Astrophysics and Space Science, he shows that the quantum vacuum could explain one more observation: the Universe’s accelerating expansion, without the need for dark energy.

“The was predicted theoretically more than 60 years ago,” Hajdukovic told PhysOrg.com. “Today, there is significant experimental evidence that the quantum vacuum exists. I have decided to combine one reality (the quantum vacuum) with one hypothesis (the negative gravitational charge of antiparticles) and to study the consequences. The hypothesis of the gravitational repulsion between matter and antimatter is older than half a century, but before me no one has used it in the combination with the quantum vacuum. … The results are surprising; there is potential to explain [the Universe’s accelerating expansion] in the framework of the quantum vacuum enriched with the gravitational repulsion between matter and antimatter.”

According to Hajdukovic, in the quantum vacuum arises from the gravitational between the positive gravitational charge of matter and the (hypothetical) negative gravitational charge of antimatter. While matter and antimatter are gravitationally self-attractive, they are mutually repulsive. (This part is similar to Massimo Villata’s theory from part 1, in which negatively charged antimatter exists in voids rather than in the quantum vacuum.) Although the quantum vacuum does not contain real matter and antimatter, short-lived and virtual antiparticles could momentarily appear and form pairs, becoming gravitational dipoles.

Dec 27, 2020

Clean Energy Breakthrough: Scientists Improve Light-Driven Water-Splitting to Produce Hydrogen

Posted by in categories: materials, particle physics

Hydrogen is a clean energy source that can be produced by splitting water molecules with light. However, it is currently impossible to achieve this on a large scale. In a recent breakthrough, scientists at Tokyo University of Science, Japan, developed a novel method that uses plasma discharge in solution to improve the performance of the photocatalyst in the water-splitting reaction. This opens doors to exploring a number of photocatalysts that can help scale-up this reaction.

The ever-worsening global environmental crisis, coupled with the depletion of fossil fuels, has motivated scientists to look for clean energy sources. Hydrogen (H2) can serve as an eco-friendly fuel, and hydrogen generation has become a hot research topic. While no one has yet found an energy-efficient and affordable way to produce hydrogen on a large scale, progress in this field is steady and various techniques have been proposed.

One such technique involves using light and catalysts (materials that speed up reactions) to split water (H2O) into hydrogen and oxygen. The catalysts have crystalline structures and the ability to separate charges at the interfaces between some of their sides. When light hits the crystal at certain angles, the energy from the light is absorbed into the crystal, causing certain electrons to become free from their original orbits around atoms in the material. As an electron leaves its original place in the crystal, a positively charged vacancy, known as a hole, is created in the structure. Generally, these “excited” states do not last long, and free electrons and holes eventually recombine.

Dec 27, 2020

Fujifilm develops technology to deliver the world’s highest 580TB storage capacity for magnetic tapes using strontium ferrite (SrFe) magnetic particles

Posted by in categories: cybercrime/malcode, information science, particle physics

“FUJIFILM Corporation (President: Kenji Sukeno) is pleased to announce that it has achieved the world’s record 317 Gbpsi recording density with magnetic tapes using a new magnetic particle called Strontium Ferrite (SrFe)*4. The record was achieved in tape running test, conducted jointly with IBM Research. This represents the development of epoch-making technology that can produce data cartridges with the capacity of 580TB (terabytes), approximately 50 times greater than the capacity of current cartridges*5. The capacity of 580TB is enough to store data equivalent to 120000 DVDs.”


TOKYO, December 162020 — FUJIFILM Corporation (President: Kenji Sukeno) is pleased to announce that it has achieved the world’s record 317 Gbpsi recording density with magnetic tapes using a new magnetic particle called Strontium Ferrite (SrFe) *4. The record was achieved in tape running test, conducted jointly with IBM Research. This represents the development of epoch-making technology that can produce data cartridges with the capacity of 580TB (terabytes), approximately 50 times greater than the capacity of current cartridges *5. The capacity of 580TB is enough to store data equivalent to 120000 DVDs.

SrFe is a magnetic material that has very high magnetic properties and is stable to maintain high performance even when processed into fine particles. It is widely used as a raw material for producing magnets for motors. Fujifilm has applied its proprietary technology to successfully develop ultra-fine SrFe magnetic particles, which can be used as a magnetic material for producing particulate magnetic tape media for data storage. The company has been conducting R&D for commercial use of SrFe magnetic particles as potential replacement of Barium Ferrite (BaFe) magnetic particles, currently used in magnetic tape data storage media. Magnetic tapes used in this test have been produced at the company’s existing coating facility, confirming the ability to support mass production and commercialization.

Continue reading “Fujifilm develops technology to deliver the world’s highest 580TB storage capacity for magnetic tapes using strontium ferrite (SrFe) magnetic particles” »

Dec 26, 2020

LHCb discovers first “open-charm” tetraquark

Posted by in category: particle physics

The LHCb experiment at CERN has developed a penchant for finding exotic combinations of quarks, the elementary particles that come together to give us composite particles such as the more familiar proton and neutron. In particular, LHCb has observed several tetraquarks, which, as the name suggests, are made of four quarks (or rather two quarks and two antiquarks). Observing these unusual particles helps scientists advance our knowledge of the strong force, one of the four known fundamental forces in the universe. At a CERN seminar held virtually on 11 August, LHCb announced the first signs of an entirely new kind of tetraquark with a mass of 2.9 GeV/c²: the first such particle with only one charm quark.

First predicted to exist in 1964, scientists have observed six kinds of quarks (and their antiquark counterparts) in the laboratory: up, down, charm, strange, top and bottom. Since quarks cannot exist freely, they group to form composite particles: three quarks or three antiquarks form “baryons” like the proton, while a quark and an antiquark form “mesons”.

The LHCb detector at the Large Hadron Collider (LHC) is devoted to the study of B mesons, which contain either a bottom or an antibottom. Shortly after being produced in proton–proton collisions at the LHC, these heavy mesons transform – or “decay” – into a variety of lighter particles, which may undergo further transformations themselves. LHCb scientists observed signs of the new tetraquark in one such decay, in which the positively charged B meson transforms into a positive D meson, a negative D meson and a positive kaon: B+→D+DK+. In total, they studied around 1300 candidates for this particular transformation in all the data the LHCb detector has recorded so far.

Dec 25, 2020

New Experiment Reveals How Light Can Push Things Around

Posted by in categories: electronics, particle physics

O,.o Circa 2018


Light might have no mass, but it can still push things around. This is known as radiation pressure. Light particles (photons) carry a momentum with them, but how this momentum is transferred is not exactly clear. However, new research has come up with a way to actually study these interactions between light and matter.

An international team constructed a very special experiment to study the momentum of light. Photons carry a tiny momentum and their effect can only be studied cumulatively. Still, there were no devices sensitive enough to measure the effect. This is why it has been so difficult to study how radiation pressure is converted into force or movement.

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Dec 25, 2020

MIT’s quantum entangled atomic clock could still be ticking after billions of years

Posted by in categories: particle physics, quantum physics

Famous medieval poet and author Geoffrey Chaucer once wrote that “‘time and tide wait for no man,” and that certainly rings true whether you’ve still got a ’90s Swatch watch strapped to your wrist, your name is Doc Brown, or you’re a brilliant scientist working on the latest atomic clock design — which employs lasers to trap and measure oscillations of quantum entangled atoms to maintain precise timekeeping.

The official time for the United States is set at the atomic clock located at the National Institute of Standards and Technology in Boulder, Colorado, where this Cesium Fountain Atomic Clock remains accurate to within one second every 300 million years. Its cesium-133 atom vibrates exactly 9, 192, 631, 770 times per second, a permanent statistic that has officially measured one second since the machine’s inception and operational rollout back in 1968.

Dec 25, 2020

Making jet fuel out of carbon dioxide

Posted by in categories: business, chemistry, particle physics, sustainability, transportation

A team of researchers affiliated with several institutions in the U.K. and one in Saudi Arabia has developed a way to produce jet fuel using carbon dioxide as a main ingredient. In their paper published in the journal Nature Communications, the group describes their process and its efficiency.

As scientists continue to look for ways to reduce the amount of emitted into the atmosphere, they have increasingly focused on certain business sectors. One of those sectors is the , which accounts for approximately 12% of transportation-related carbon dioxide emissions. Curbing in the aviation industry has proved to be challenging due to the difficulty of fitting heavy batteries inside of aircraft. In this new effort, the researchers have developed a that can be used to produce carbon-neutral jet fuel.

The researchers used a process called the organic combustion method to convert carbon dioxide in the air into jet fuel and other products. It involved using an iron catalyst (with added potassium and manganese) along with hydrogen, citric acid and carbon dioxide heated to 350 degrees C. The process forced the apart from the oxygen atoms in CO2 molecules, which then bonded with hydrogen atoms, producing the kind of hydrocarbon molecules that comprise liquid jet fuel. The process also resulted in the creation of water molecules and other products.

Dec 25, 2020

Jack Steinberger (1921–2020)

Posted by in category: particle physics

Particle physicist who shared Nobel for discovering muon neutrinos.

Dec 24, 2020

Beam me up: long-distance quantum teleportation has happened for the first time ever

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

Raise your hand if you ever wanted to get beamed onto the transport deck of the USS Enterprise. Maybe we haven’t reached the point of teleporting entire human beings yet (sorry Scotty), but what we have achieved is a huge breakthrough towards quantum internet.

Led by Caltech, a collaborative team from Fermilab, NASA’s Jet Propulsion Lab, Harvard University, the University of Calgary and AT&T have now successfully teleported qubits (basic units of quantum info) across almost 14 miles of fiber optic cables with 90 percent precision. This is because of quantum entanglement, the phenomenon in which quantum particles which are mysteriously “entangled” behave exactly the same even when far away from each other.