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Archive for the ‘particle physics’ category: Page 312

Nov 16, 2021

Element Synthesis in the Universe: Where Does Gold Come From?

Posted by in categories: chemistry, computing, cosmology, particle physics

How are chemical elements produced in our Universe? Where do heavy elements like gold and uranium come from? Using computer simulations, a research team from the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, together with colleagues from Belgium and Japan, shows that the synthesis of heavy elements is typical for certain black holes with orbiting matter accumulations, so-called accretion disks. The predicted abundance of the formed elements provides insight into which heavy elements need to be studied in future laboratories — such as the Facility for Antiproton and Ion Research (FAIR), which is currently under construction — to unravel the origin of heavy elements. The results are published in the journal Monthly Notices of the Royal Astronomical Society.

All heavy elements on Earth today were formed under extreme conditions in astrophysical environments: inside stars, in stellar explosions, and during the collision of neutron stars. Researchers are intrigued with the question in which of these astrophysical events the appropriate conditions for the formation of the heaviest elements, such as gold or uranium, exist. The spectacular first observation of gravitational waves and electromagnetic radiation originating from a neutron star merger in 2017 suggested that many heavy elements can be produced and released in these cosmic collisions. However, the question remains open as to when and why the material is ejected and whether there may be other scenarios in which heavy elements can be produced.

Promising candidates for heavy element production are black holes orbited by an accretion disk of dense and hot matter. Such a system is formed both after the merger of two massive neutron stars and during a so-called collapsar, the collapse and subsequent explosion of a rotating star. The internal composition of such accretion disks has so far not been well understood, particularly with respect to the conditions under which an excess of neutrons forms. A high number of neutrons is a basic requirement for the synthesis of heavy elements, as it enables the rapid neutron-capture process or r-process. Nearly massless neutrinos play a key role in this process, as they enable conversion between protons and neutrons.

Nov 16, 2021

A dynamical quantum Cheshire Cat effect and implications for counterfactual communication

Posted by in categories: particle physics, quantum physics

In quantum mechanics, counterfactual behaviours are generally associated with particles being affected by events taking place where they can’t be found. Here, the authors consider extended quantum Cheshire cat scenarios where a particle can be influenced in regions where only its disembodied property has entered.

Nov 16, 2021

IBM claims it has made a major breakthrough in constructing a quantum computer

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

IBM says it has built a quantum processor that it says cannot be simulated by a classical computer.

If true, the processor would represent a major breakthrough in quantum computing, which its proponents say could lead to radical changes in how we are able to deal with information.

The company says that the quantum processor is so capable that to simulate its capabilities with a traditional computer, one would require more bits than there are atoms in every person in existence.

Nov 15, 2021

Fusion Breakthrough: At the Brink of Fusion Ignition at National Ignition Facility

Posted by in categories: nuclear energy, particle physics

Experiments conducted in August achieved a record yield of more than 1.3 megajoules.

After decades of inertial confinement fusion research, a record yield of more than 1.3 megajoules (MJ) from fusion reactions was achieved in the laboratory for the first time during an experiment at Lawrence Livermore National Laboratory’s (LLNL) National Ignition Facility (NIF) on August 8, 2021. These results mark an 8-fold improvement over experiments conducted in spring 2021 and a 25-fold increase over NIF’s 2018 record yield (Figure 1).

NIF precisely guides, amplifies, reflects, and focuses 192 powerful laser beams into a target about the size of a pencil eraser in a few billionths of a second. NIF generates temperatures in the target of more than 180 million F and pressures of more than 100 billion Earth atmospheres. Those extreme conditions cause hydrogen atoms in the target to fuse and release energy in a controlled thermonuclear reaction.

Nov 14, 2021

Dark Matter Birthed More of Itself From Regular Matter, Claims Wild New Paper

Posted by in categories: cosmology, particle physics

There’s a lot we still don’t know about dark matter – that mysterious, invisible mass that could make up as much as 85 percent of everything around us – but a new paper outlines a rather unusual hypothesis about the very creation of the stuff.

In short: dark matter creates dark matter. The idea is that at some point in the early stages of the Universe, dark matter particles were able to create more dark matter particles out of particles of regular matter, which would go some way to explaining why there’s now so much of the stuff about.

The new research builds on earlier proposals of a ‘thermal bath’, where regular matter in the form of plasma produced the first bits of dark matter – initial particles which could then have had the power to transform heat bath particles into more dark matter.

Nov 14, 2021

Physicists take the most detailed image of atoms to date

Posted by in categories: information science, mobile phones, particle physics

Physicists just put Apple’s latest iPhone to shame, taking the most detailed image of atoms to date with a device that magnifies images 100 million times, reports. The researchers, who set the record for the highest resolution microscope in 2018, outdid themselves with a study published last month. Using a method called electron ptychography, in which a beam of electrons is shot at an object and bounced off to create a scan that algorithms use to reverse engineer the above image, were used to visualize the sample. Previously, scientists could only use this method to image objects that were a few atoms thick. But the new study lays out a technique that can image samples 30 to 50 nanometers wide—a more than 10-fold increase in resolution, they report in. The breakthrough could help develop more efficient electronics and batteries, a process that requires visualizing components on the atomic level.

Nov 14, 2021

Physicists develop a device that could provide conclusive evidence for the existence (or not) of non-Abelian anyons

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

What kinds of ‘particles’ are allowed by nature? The answer lies in the theory of quantum mechanics, which describes the microscopic world.

In a bid to stretch the boundaries of our understanding of the world, UC Santa Barbara researchers have developed a device that could prove the existence of non-Abelian anyons, a that has been mathematically predicted to exist in two-dimensional space, but so far not conclusively shown. The existence of these particles would pave the way toward major advances in topological quantum computing.

In a study that appears in the journal Nature, physicist Andrea Young, his graduate student Sasha Zibrov and their colleagues have taken a leap toward finding conclusive evidence for non-Abelian anyons. Using graphene, an atomically thin material derived from graphite (a form of carbon), they developed an extremely low-defect, highly tunable device in which non-Abelian anyons should be much more accessible. First, a little background: In our three-dimensional universe, elementary particles can be either fermions or bosons: think electrons (fermions) or the Higgs (a boson).

Nov 12, 2021

Researchers achieve first quantum simulation of baryons

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

A team of researchers led by an Institute for Quantum Computing (IQC) faculty member performed the first-ever simulation of baryons—fundamental quantum particles—on a quantum computer.

With their results, the team has taken a step towards more complex quantum simulations that will allow scientists to study neutron stars, learn more about the earliest moments of the universe, and realize the revolutionary potential of quantum computers.

Continue reading “Researchers achieve first quantum simulation of baryons” »

Nov 11, 2021

New Insights Into The Structure Of The Neutron

Posted by in categories: particle physics, space

All known atomic nuclei and therefore almost all visible matter consists of protons and neutrons, yet many of the properties of these omnipresent natural building blocks remain unknown. As an uncharged particle, the neutron in particular resists many types of measurement and 90 years after its discovery there are still many unanswered questions regarding its size and lifetime, among other things.

The neutron consists of three quarks which whirl around inside it, held together by gluons. Physicists use electromagnetic form factors to describe this dynamic inner structure of the neutron. These form factors represent an average distribution of electric charge and magnetization within the neutron and can be determined by means of experimentation.

Blank space on the form factor map filled with precise data.

Nov 10, 2021

Adding sound to quantum simulations

Posted by in categories: media & arts, particle physics, quantum physics

When sound was first incorporated into movies in the 1920s, it opened up new possibilities for filmmakers such as music and spoken dialogue. Physicists may be on the verge of a similar revolution, thanks to a new device developed at Stanford University that promises to bring an audio dimension to previously silent quantum science experiments.

In particular, it could bring sound to a common quantum science setup known as an , which uses a crisscrossing mesh of laser beams to arrange atoms in an orderly manner resembling a crystal. This tool is commonly used to study the fundamental characteristics of solids and other phases of matter that have repeating geometries. A shortcoming of these lattices, however, is that they are silent.

“Without sound or vibration, we miss a crucial degree of freedom that exists in real materials,” said Benjamin Lev, associate professor of applied physics and of physics, who set his sights on this issue when he first came to Stanford in 2011. “It’s like making soup and forgetting the salt; it really takes the flavor out of the quantum ‘soup.’”.