Menu

Blog

Archive for the ‘particle physics’ category: Page 263

Nov 28, 2021

What is the Nuclear EMC effect? Scientists shed light on a physics-defying mystery

Posted by in category: particle physics

Nuclear physicists have observed something strange in the heart of an atom that defies existing science. They’re on a mission to figure out why.

Nov 27, 2021

Tachyons: Facts about these faster-than-light particles

Posted by in category: particle physics

Tachyons are not just the stuff of science fiction.


Tachyons are hypothetical particles that move faster than the speed of light and travel backward through time. Whether they exist is still up for debate.

Nov 27, 2021

Quantum superposition of thermodynamic evolutions with opposing time’s arrows

Posted by in categories: particle physics, quantum physics

Taking a gas enclosed in a vessel as a pictorial example, the aforementioned state can be constructed by entangling the position of the piston with a further auxiliary quantum system, thereby establishing a quantum superposition of the following two processes: (i) a process wherein the gas particles are initially in thermal equilibrium confined in one half of the vessel by a piston, and the piston is pulled outwards, and (ii) the reverse process, in which the piston is pushed towards the gas, starting from an initial state where the gas occupies the entire vessel in thermal equilibrium.

We will now measure the work of the system undergoing the above-mentioned superposition of forward and time-reversal dynamics. In order to implement such a measurement, we formally construct a procedure described by a set of measurement operators forming a completely positive and trace-preserving (CPTP) map. In this regard, we will refer to a standard TPM procedure to measure work in quantum thermodynamic processes13. Implementations of the TPM in quantum setups25,26,27,28,29, as well as suitable extensions30,31,32,33, have recently received increasing attention. Our procedure can be seen as a generalisation of the TPM scheme to situations where different thermodynamic processes are allowed to be superposed, and can consequently interfere.

In the TPM scheme, work is defined as the energy difference between the initial and final states of the system, which are measured through ideal projective measurements of the system Hamiltonian implemented before and after the thermodynamic process associated with the protocol Λ34,35. This measurement scheme can be performed, individually, both for the forward and the time-reversal processes, enabling the construction of the work probability distributions P (W) and \(\tilde{P}(W)\) 0, respectively.

Nov 27, 2021

Heavy antimatter created in gold collisions

Posted by in category: particle physics

Circa 2010


Most massive antimatter nucleus yet identified in particle experiments.

Nov 27, 2021

How To Make and Trap Antimatter

Posted by in categories: particle physics, space travel

Circa 2017


Antimatter sounds mysterious and powerful. In science fiction, it often has properties like defying gravity or taking on opposite colors. But in reality, antimatter is really no different than regular matter, except that antimatter atoms have positrons instead of electrons and antiprotons instead of protons. At CERN in Switzerland, scientists have actually been able to create antimatter and store it in a magnetic field that keeps it from touching regular matter. If that happens, the antimatter annihilates, producing a burst of energy. In sci-fi like Star Trek, this energy is used to power spaceships. We’re still very far from something like that, but it’s still pretty incredible that we can create something that was for a long time just a hypothesis.

Nov 27, 2021

Machine learning solves the who’s who problem in NMR spectra of organic crystals

Posted by in categories: chemistry, particle physics, robotics/AI

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.

Nov 26, 2021

Scientists Make Big Step Towards Making Antimatter Stand Still

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

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.

Continue reading “Scientists Make Big Step Towards Making Antimatter Stand Still” »

Nov 26, 2021

New Ultrahard Diamond Glass Synthesized Using Carbon Buckyballs

Posted by in categories: chemistry, particle physics

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.

Nov 26, 2021

Electrons Set the Stage for Neutrino Experiments — Solving Mystery of the Origins of Our Matter-Dominated Universe

Posted by in category: particle physics

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.

Nov 26, 2021

Solving a Cosmic Conundrum: “Perfect Fluid” Brings Us Closer to Understanding How Our Universe Began

Posted by in category: particle physics

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.

Continue reading “Solving a Cosmic Conundrum: ‘Perfect Fluid’ Brings Us Closer to Understanding How Our Universe Began” »