БЛОГ

Archive for the ‘particle physics’ category: Page 173

Apr 15, 2020

Neutrinos could shed light on why the Universe has so much more matter than antimatter

Posted by in categories: particle physics, space

A major finding in particle physics reminds us of the importance of robust preliminary results — and paves the way for more exciting discoveries.

Apr 15, 2020

A quantum metasurface that can simultaneously control multiple properties of light

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

:oooo.


Metasurfaces are artificial materials designed at the nanoscale, which can control the scattering of light with exceptionally high precision. Over the past decade or so, these materials have been used to create a variety of technological tools ranging from sensors to lenses and imaging techniques.

A research team led by Mikhail Lukin at Harvard University has recently proposed a new type of metasurface that can control both the spatiotemporal and of transmitted and reflected . In a paper published in Nature Physics, the team showed that realizing a quantum metasurface is possible and could be achieved by entangling the macroscopic response of thin atom arrays to light.

Continue reading “A quantum metasurface that can simultaneously control multiple properties of light” »

Apr 15, 2020

Researchers solve puzzle of Compton scattering: New approach for testing theories in quantum mechanics

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

When the American physicist Arthur Compton discovered that light waves behave like particles in 1922, and could knock electrons out of atoms during an impact experiment, it was a milestone for quantum mechanics. Five years later, Compton received the Nobel Prize for this discovery. Compton used very shortwave light with high energy for his experiment, which enabled him to neglect the binding energy of the electron to the atomic nucleus. Compton simply assumed for his calculations that the electron rested freely in space.

During the following 90 years up to the present, numerous experiments and calculations have been carried out with regard to Compton scattering that continually revealed asymmetries and posed riddles. For example, it was observed that in certain experiments, seemed to be lost when the motion energy of the electrons and light particles (photons) after the collision were compared with the energy of the photons before the collision. Since energy cannot simply disappear, it was assumed that in these cases, contrary to Compton’s simplified assumption, the influence of the on the photon-electron collision could not be neglected.

For the first time in an impact experiment with photons, a team of physicists led by Professor Reinhard Dörner and doctoral candidate Max Kircher at Goethe University Frankfurt has now simultaneously observed the ejected electrons and the motion of the nucleus. To do so, they irradiated helium atoms with X-rays from the X-ray source PETRA III at the Hamburg accelerator facility DESY. They detected the ejected and the charged rest of the atom (ions) in a COLTRIMS reaction microscope, an apparatus that Dörner helped develop and which is able to make ultrafast reactive processes in atoms and molecules visible.

Apr 14, 2020

We may have spotted a parallel universe going backwards in time

Posted by in categories: cosmology, particle physics

Strange particles observed by an experiment in Antarctica could be evidence of an alternative reality where everything is upside down.

Apr 14, 2020

Physicists to improve plasma fusion mirror devices with $5 million grant

Posted by in categories: nuclear energy, particle physics

Fusion research began in earnest in the 1960s, when scientists developed mirror machines. These linear tubes have pinched magnetic field lines on either end that act like mirrors, reflecting the charged plasma particles inward and retaining them and their heat in the machine. American researchers halted mirror research three decades ago, mainly due to an inability to contain the plasma.

WHAM will essentially take the team’s research back to the mirror machine days, but with significant upgrades.

“We hope to go well beyond what was done in the mirror program because we have access to very-high-field superconducting magnets like those being built by our partners for toroidal (donut-shaped) plasmas,” Forest says. “These magnets and heating systems simply weren’t available 20 years ago. It’s a new look at an older concept using new technology.”

Continue reading “Physicists to improve plasma fusion mirror devices with $5 million grant” »

Apr 14, 2020

Higgs turning up everywhere, this time in paint

Posted by in categories: particle physics, quantum physics

:oooo circa 2009.


The portrait of Peter Higgs is on display at the University of Edinburgh’s School of Informatics. Photograph: Ken Currie.

It seems that Peter Higgs, despite his known aversion to publicity is turning up everywhere. Of course the potential discovery of the particle in the next few years by either/both of the Large Hadron Collider at CERN and the Tevatron at Fermilab is bringing a lot more attention to him, and a little to the other theorists, such as Guralnik, Hagen, Kibble, Brout, and Englert, who also developed the ideas behind a mass-giving spontaneously symmetry broken quantum field and its manifestation as a particle, now known as the Higgs boson. (Yep, that sounds scary because it gets technical.)

Continue reading “Higgs turning up everywhere, this time in paint” »

Apr 14, 2020

US4663932A — Dipolar force field propulsion system

Posted by in category: particle physics

A dipolar force field propulsion system having a alternating electric field source for producing electromotive lines of force which in a first direction and which vary at a selected and having an electric field of a predetermined magnitude, a source of an alternating magnetic field having magnetic lines of force which in a second direction which is at a predetermined angle to the first direction of the electromotive lines of force and which cross and intercept the electromotive line of force at a predetermined location defining a force field region and wherein the of the alternating magnetic field substantially equal to the of the alternating electric field and at a selected in phase angle therewith and wherein the magnetic field has a flux which when multiplied times the selected is less than a known characteristic field ionization limit; a source of neutral particles of matter having a selected dipole characteristic and having a known characteristic field ionization limit which is greater than the magnitude of the electric field and wherein the dipoles of the particles of matter are capable of being driven into cyclic rotation at the selected by the electric field to produce a reactive thrust, a vaporizing stage which vaporizes said particles of matter into a gaseous state at a selected temperature, and a transporting system for transporting the vaporized particles of matter into the force field defined by the crossing electromotive lines of force and the magnetic lines of force.

Apr 14, 2020

Collisions reveal new evidence of ‘anyon’ quasiparticles’ existence

Posted by in category: particle physics

Sometimes, two dimensions are better than three.

In the three-dimensional world we live in, there are two classes of elementary particles: bosons and fermions. But in two dimensions, theoretical physicists predict, there’s another option: anyons. Now, scientists report new evidence that anyons exist and that they behave unlike any known particle. Using a tiny “collider,” researchers flung presumed anyons at one another to help confirm their identities, physicists report in the April 10 Science.

All known elementary particles can be classified either fermions or bosons. Electrons, for example, are fermions. Bosons include photons, which are particles of light, and the famed Higgs boson, which explains how particles get mass (SN: 7/4/12). The two classes behave differently: Fermions are loners and avoid one another, while bosons can clump together.

Continue reading “Collisions reveal new evidence of ‘anyon’ quasiparticles’ existence” »

Apr 14, 2020

New handle for controlling electromagnetic properties could enable spintronic computing

Posted by in categories: computing, particle physics, space

Materials scientists at Duke University have shown the first clear example that a material’s transition into a magnet can control instabilities in its crystalline structure that cause it to change from a conductor to an insulator.

If researchers can learn to control this unique connection between identified in hexagonal iron sulfide, it could enable new technologies such as spintronic computing. The results appear April 13 in the journal Nature Physics.

Commonly known as troilite, hexagonal iron sulfide can be found natively on Earth but is more abundant in meteorites, particularly those originating from the Moon and Mars. Rarely encountered in the Earth’s crust, most troilite on Earth is believed to have originated from space.

Apr 14, 2020

Research identifies detection constraints for dark photons

Posted by in categories: cosmology, particle physics

:oooo.


Past cosmological and astrophysical observations suggest that over one quarter of the universe’s energy density is made up of a non-conventional type of matter known as dark matter. This type of matter is believed to be composed of particles that do not absorb, emit or reflect light, and thus cannot be observed directly using conventional detection methods.

Researchers worldwide have carried out studies aimed at detecting dark matter in the universe, yet so far, none of them has been successful. Even the for dark matter, weakly interacting massive particles (WIMPs), have not yet been observed experimentally.

Continue reading “Research identifies detection constraints for dark photons” »