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Category: particle physics – Page 366

Solid-state nuclear magnetic resonance (NMR) spectroscopy—a technique that measures the frequencies emitted by the nuclei of some atoms exposed to radio waves in a strong magnetic field—can be used to determine chemical and 3D structures as well as the dynamics of molecules and materials.

A necessary initial step in the analysis is the so-called chemical shift assignment. This involves assigning each peak in the NMR spectrum to a given atom in the molecule or material under investigation. This can be a particularly complicated task. Assigning chemical shifts experimentally can be challenging and generally requires time-consuming multi-dimensional correlation experiments. Assignment by comparison to statistical analysis of experimental chemical shift databases would be an alternative solution, but there is no such for molecular solids.

A team of researchers including EPFL professors Lyndon Emsley, head of the Laboratory of Magnetic Resonance, Michele Ceriotti, head of the Laboratory of Computational Science and Modeling and Ph.D. student Manuel Cordova decided to tackle this problem by developing a method of assigning NMR spectra of organic crystals probabilistically, directly from their 2D chemical structures.

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Scientists have been able to trap antimatter particles using a combination of electric and magnetic fields. Antiprotons have been stored for over a year, while antimatter electrons have been stored for shorter periods of time, due to their lower mass. In 2011, researchers at CERN announced that they had stored antihydrogen for over 1,000 seconds.

While scientists have been able to store and manipulate small quantities of antimatter, they have not been able to answer why antimatter is so rare in the universe. According to Einstein’s famous equation E = mc2, energy should convert into matter and antimatter in equal quantities. And, immediately after the Big Bang, there was a lot of energy. Accordingly, we should see as much antimatter as matter in our universe, and yet we don’t. This is a pressing unsolved mystery of modern physics.

According to Einstein’s equations, as well as other modern theories of antimatter, antimatter should be exactly the same as ordinary matter, with only the electric charges reversed. Thus, antimatter hydrogen should emit light just like ordinary hydrogen does, and with exactly the same wavelengths. In fact, an experiment showing exactly this behavior was reported in early 2020. This was a triumph for current theories, but meant no explanation for the universe’s preference of matter was found.

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It is the hardest known glass with the highest thermal conductivity among all glass materials.

Carnegie’s Yingwei Fei and Lin Wang were part of an international research team that synthesized a new ultrahard form of carbon glass with a wealth of potential practical applications for devices and electronics. It is the hardest known glass with the highest thermal conductivity among all glass materials. Their findings are published in Nature.

Function follows form when it comes to understanding the properties of a material. How its atoms are chemically bonded to each other, and their resulting structural arrangement, determines a material’s physical qualities—both those that are observable by the naked eye and those that are only revealed by scientific probing.

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Early-career nuclear physicists show that a better understanding of how neutrinos interact with matter is needed to make the most of upcoming experiments.

Neutrinos may be the key to finally solving a mystery of the origins of our matter-dominated universe, and preparations for two major, billion-dollar experiments are underway to reveal the particles’ secrets. Now, a team of nuclear physicists have turned to the humble electron to provide insight for how these experiments can better prepare to capture critical information. Their research, which was carried out at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility and recently published in Nature, reveals that major updates to neutrino models are needed for the experiments to achieve high-precision results.

Neutrinos are ubiquitous, generated in copious numbers by stars throughout our universe. Though prevalent, these shy particles rarely interact with matter, making them very difficult to study.

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How to Catch a Perfect Wave: Scientists Take a Closer Look Inside the Perfect Fluid

Berkeley Lab research brings us closer to understanding how our universe began.

Scientists have reported new clues to solving a cosmic conundrum: How the quark-gluon plasma.

Plasma is one of the four fundamental states of matter, along with solid, liquid, and gas. It is an ionized gas consisting of positive ions and free electrons. It was first described by chemist Irving Langmuir in the 1920s.

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Friends Lunch with a Member.

Topic: Negative Energy, Quantum Information and Causality.
Speaker: Adam Levine.
Date: November 19, 2021

Einstein’s equations of gravity show that too much negative energy can lead to causality violations and causal paradoxes such as the so-called “grandfather paradox. In quantum mechanics, however, negative energies can arise from intrinsically quantum effects, such as the Casimir effect. Thus, it is not clear that gravity and quantum mechanics can be self-consistently combined. In this talk, Levine will discuss modern advances in understanding the connection between energy and causality in gravity and how quantum gravity avoids obvious paradoxes. He will also explore how this line of thought leads to new insights in quantum field theory, which governs particle physics.

As a physicist, Adam Levine’s research aims to understand the structure of entanglement in quantum field theories and quantum gravity through use of techniques from the study of conformal field theories, as well as quantum information theory and AdS/CFT. With support from the National Science Foundation, Adam is a long term Member in the School of Natural Sciences. He received his Ph.D. from University of California, Berkeley (2019), was a Graduate Fellow at the Kavli Institute for Theoretical Physics (2018), a National Defense Science and Engineering Graduate Fellow (2017−2020), and received the Jeffrey Willick Memorial Award for Outstanding Scholarship in Astrophysics from Stanford University (2015).

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Physicists have detected “ghost particles” in the Large Hadron Collider for the first time. An experiment called FASER picked up telltale signals of neutrinos being produced in particle collisions, which can help scientists better understand key physics.

Neutrinos are elementary particles that are electrically neutral, extremely light and rarely interact with particles of matter. That makes them tricky to detect, even though they’re very common – in fact, there are billions of neutrinos streaming through your body right now. Because of this, they’re often described as ghost particles.

Neutrinos are produced in stars, supernovae, quasars. radioactive decay and from cosmic rays interacting with atoms in the Earth’s atmosphere. It’s long been thought that particle accelerators like the LHC should be making them too, but without the right instruments they would just zip away undetected.

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ROME, July 2 (Reuters) — A United Nations-backed scientific research centre has teamed up with an Italian tech firm to explore whether laser light can be used to kill coronavirus particles suspended in the air and help keep indoor spaces safe.

The joint effort between the International Centre for Genetic Engineering and Biotechnology (ICGEB) of Trieste, a city in the north of Italy, and the nearby Eltech K-Laser company, was launched last year as COVID-19 was battering the country.

They created a device that forces air through a sterilization chamber which contains a laser beam filter that pulverizes viruses and bacteria.

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Researchers prepare ‘new type of matter’ to conduct classic wave-particle duality experiment.

The iconic quantum double-slit experiment, which reveals how matter can behave like waves that displays interference and superposition, has for the first time been demonstrated with individual molecules as the slits.

Richard Feynman once said that the double-slit experiment reveals the central puzzles of quantum mechanics, putting us ‘up against the paradoxes and mysteries and peculiarities of nature’.

Richard Zare, Nandini Mukherjee and their co-workers at Stanford University, US, have now shown that when helium atoms collide with deuterium molecules (D2) in quantum superposition of states, the scattering can take two different paths that interfere with one another. The researchers reveal the interference by looking at its effects on the scattered D2 molecules, which lose rotational energy in the collision.

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