Circa 2018
Laser and particle system produces three-dimensional moving images that appear to float in thin air.
Category: particle physics – Page 475
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.
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?
It’s a non-linear integral equation with two variables. Such an equation is so complex that you do actually think there can’t possibly be any formula for a solution. Two variables alone are a challenge in themselves, and there are no established approaches for finding a solution for non-linear integral equations. Nevertheless, again and again during those 10 years there were glimmers of hope and as a result, and despite all the difficulties, I thought finding an explicit formula for a solution – expressed through known functions – was actually possible.
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.
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.
Indeed, cold plasma is so good at its job, it can kill 99.9 percent of airborne viruses, researchers at the University of Michigan found. Their research is published in the Journal of Physics D: Applied 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.
The behavior of the quantum world is beyond weird. Objects being in multiple places at once, communicating faster than light, or simultaneously experiencing multiple entire timelines … that then talk to each other. The rules governing the tiny quantum world of atoms and photons seem alien. And yet we have a set of rules that give us incredible power in predicting the behavior of a quantum system – rules encapsulated in the mathematics of quantum mechanics. Despite its stunning success, we’re now nearly a century past the foundation of quantum mechanics and physicists are still debating how to interpret its equations and the weirdness they represent.
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.
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.