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Archive for the ‘particle physics’ category: Page 354

May 5, 2020

Four years of calculations lead to new insights into muon anomaly

Posted by in categories: particle physics, supercomputing

Two decades ago, an experiment at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory pinpointed a mysterious mismatch between established particle physics theory and actual lab measurements. When researchers gauged the behavior of a subatomic particle called the muon, the results did not agree with theoretical calculations, posing a potential challenge to the Standard Model—our current understanding of how the universe works.

Ever since then, scientists around the world have been trying to verify this discrepancy and determine its significance. The answer could either uphold the Standard Model, which defines all of the known subatomic particles and how they interact, or introduce the possibility of an entirely undiscovered physics. A multi-institutional research team (including Brookhaven, Columbia University, and the universities of Connecticut, Nagoya and Regensburg, RIKEN) have used Argonne National Laboratory’s Mira supercomputer to help narrow down the possible explanations for the discrepancy, delivering a newly precise theoretical calculation that refines one piece of this very complex puzzle. The work, funded in part by the DOE’s Office of Science through its Office of High Energy Physics and Advanced Scientific Computing Research programs, has been published in the journal Physical Review Letters.

A muon is a heavier version of the electron and has the same electric charge. The measurement in question is of the muon’s magnetic moment, which defines how the particle wobbles when it interacts with an external magnetic field. The earlier Brookhaven experiment, known as Muon g-2, examined muons as they interacted with an electromagnet storage ring 50 feet in diameter. The experimental results diverged from the value predicted by theory by an extremely small amount measured in parts per million, but in the realm of the Standard Model, such a difference is big enough to be notable.

May 5, 2020

Mathematician discusses solving a seemingly unsolvable equation

Posted by in categories: information science, mathematics, particle physics

Circa 2018


After 10 years, Prof. Raimar Wulkenhaar from the University of Münster’s Mathematical Institute and his colleague Dr. Erik Panzer from the University of Oxford have solved a mathematical equation which was considered to be unsolvable. The equation is to be used to find answers to questions posed by elementary particle physics. In this interview with Christina Heimken, Wulkenhaar looks back on the challenges encountered in looking for the formula for a solution and he explains why the work is not yet finished.

You worked on the solution to the equation for 10 years. What made this equation so difficult to solve?

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May 4, 2020

To make an atom-sized machine, you need a quantum mechanic

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

Here’s a new chapter in the story of the miniaturisation of machines: researchers in a laboratory in Singapore have shown that a single atom can function as either an engine or a fridge. Such a device could be engineered into future computers and fuel cells to control energy flows.

“Think about how your computer or laptop has a lot of things inside it that heat up. Today you cool that with a fan that blows air. In nanomachines or quantum computers, small devices that do cooling could be something useful,” says Dario Poletti from the Singapore University of Technology and Design (SUTD).

This work gives new insight into the mechanics of such devices. The work is a collaboration involving researchers at the Centre for Quantum Technologies (CQT) and Department of Physics at the National University of Singapore (NUS), SUTD and at the University of Augsburg in Germany. The results were published in the peer-reviewed journal npj Quantum Information on 1 May.

May 3, 2020

Scientists Invent Device That Can Kill 99.9 Percent Of Airborne Viruses

Posted by in categories: food, particle physics

Non-thermal (or cold) plasma has been around for years. A version of this technology is incorporated into power plants to stop particles being released into the atmosphere. It can also be used to decontaminate food.

Now, researchers have developed an exciting new use for the stuff – the eradication of potentially dangerous viruses floating in the air.

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May 3, 2020

Philip W. Anderson (1923–2020)

Posted by in category: particle physics

Nobel winner who transformed condensed-matter and particle physics.

May 3, 2020

Physicists identify unique signature to confirm quark-gluon plasma in universe

Posted by in category: particle physics

Simulations show that QGP could form in immediate aftermath of neutron star merger.

May 2, 2020

Does Consciousness Influence Quantum Mechanics?

Posted by in categories: information science, particle physics, quantum physics

Education Saturday with Space Time.


It’s not surprising that the profound weirdness of the quantum world has inspired some outlandish explanations – nor that these have strayed into the realm of what we might call mysticism. One particularly pervasive notion is the idea that consciousness can directly influence quantum systems – and so influence reality. Today we’re going to see where this idea comes from, and whether quantum theory really supports it.

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May 1, 2020

Imaging nematic transitions in iron pnictide superconductors

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

Researchers at Stanford University have recently carried out an in-depth study of nematic transitions in iron pnictide superconductors. Their paper, published in Nature Physics, presents new imaging data of these transitions collected using a microscope they invented, dubbed the scanning quantum cryogenic atom microscope (SQCRAMscope).

“We invented a new type of scanning probe microscope a few years ago,” Benjamin L. Lev, the researcher who led the study, told Phys.org. “One can think of it like a normal optical microscope, but instead of the lens focused on some sample slide, the focus is on a quantum gas of atoms that are levitated near the sample.”

In the new microscope invented by Lev and his colleagues, atoms are levitated from an ‘atom chip’ trapping device using magnetic fields, until they are merely a micron above the sample slide. These atoms can transduce the magnetic fields that emanate from the sample into the light collected by the microscope’s lens. As a result, SQCRAMscope can be used to image magnetic fields.

Apr 29, 2020

A Hypothesis on Production of Tachyons

Posted by in categories: information science, particle physics

An exact solution of the Einstein—Maxwell equations yields a general relativistic picture of the tachyonic phenomenon, suggesting a hypothesis on the tachyon creation. The hypothesis says that the tachyon is produced when a neutral and very heavy (over 75 GeV/c^2) subatomic particle is placed in electric and magnetic fields that are perpendicular, very strong (over 6.9 × 1017 esu/cm^2 or oersted), and the squared ratio of their strength lies in the interval (1,5]. Such conditions can occur when nonpositive subatomic particles of high energy strike atomic nuclei other than the proton. The kinematical relations for the produced tachyon are given. Previous searches for tachyons in air showers and some possible causes of their negative results are discussed.

Apr 29, 2020

Exact Phoretic Interaction of Two Chemically Active Particles

Posted by in category: particle physics

We study the nonequilibrium interaction of two isotropic chemically active particles taking into account the exact near-field chemical interactions as well as hydrodynamic interactions. We identify regions in the parameter space wherein the dynamical system describing the two particles can have a fixed point—a phenomenon that cannot be captured under the far-field approximation. We find that, due to near-field effects, the particles may reach a stable equilibrium at a nonzero gap size or make a complex that can dissociate in the presence of sufficiently strong noise. We explicitly show that the near-field effects originate from a self-generated neighbor-reflected chemical gradient, similar to interactions of a self-propelling phoretic particle and a flat substrate.