Physics News and Discussions

weatheriscool
Posts: 12967
Joined: Sun May 16, 2021 6:16 pm

Re: Physics News and Discussions

Post by weatheriscool »

The ATLAS collaboration observes the electroweak production of two jets and a Z-boson pair
https://phys.org/news/2023-04-atlas-col ... -jets.html
by Ingrid Fadelli , Phys.org
The ATLAS collaboration, the large research consortium involved in analyzing data collected by the ATLAS particle collider at CERN, recently observed the electroweak production of two Z bosons and two jets. This crucial observation, presented in Nature Physics, could greatly contribute to the understanding of standard model (SM) particle physics.

The SM of particle physics is a well-established theory describing the building blocks and fundamental forces in the universe. This model describes weak bosons (i.e., bosons responsible for the so-called 'weak force') as mediators of the electroweak interaction.

The scattering of massive weak bosons, such as W and Z bosons, is constrained specifically to interactions, where the mediators themselves carry the charge of these interactions. This scattering, also known as vector-boson scattering (VBS), also involves a type of Feynman diagrams or vertices known (i.e., quartic gauge vertices) that physicists have so far been unable to experimentally probe through other physical processes.

"Quartic gauge vertices are a so far unconfirmed section of the SM, which is, however of central importance to the self-consistency of the model," Gabriela Navarro, part of the ATLAS collaboration, told Phys.org. "An example for this self-consistency is a delicate cancelation of scattering amplitudes involving Triple Gauge Vertices, Quartic Gauge Vertices and Vertices involving the Higgs Boson. A study of these processes is an independent and crucial test of the BEH-Mechanism for breaking the electroweak symmetry in the SM (EWSB)."
weatheriscool
Posts: 12967
Joined: Sun May 16, 2021 6:16 pm

Re: Physics News and Discussions

Post by weatheriscool »

Breakthrough in magnetic quantum material paves way for ultra-fast sustainable computers
https://phys.org/news/2023-04-breakthro ... paves.html
by Chalmers University of Technology
The discovery of new quantum materials with magnetic properties could pave the way for ultra-fast and considerably more energy-efficient computers and mobile devices. So far, these types of materials have been shown to work only in extremely cold temperatures. Now, a research team at Chalmers University of Technology in Sweden are the first to make a device made of a two-dimensional magnetic quantum material work in room temperature.

Today's rapid IT expansion generates enormous amounts of digital data that needs to be stored, processed, and communicated. This comes with an ever-increasing need for energy—projected to consume more than 30% of the world's total energy consumption by 2050. To combat the problem, the research community has entered a new paradigm in materials science. The research and development of two-dimensional quantum materials, that form in sheets and are only a few atoms thick, have opened new doors for sustainable, faster and more energy-efficient data storage and processing in computers and mobiles.
weatheriscool
Posts: 12967
Joined: Sun May 16, 2021 6:16 pm

Re: Physics News and Discussions

Post by weatheriscool »

Particle trio exceeds expectations at Large Hadron Collider
https://phys.org/news/2023-04-particle- ... adron.html
by Chris Patrick, SLAC National Accelerator Laboratory
The ATLAS experiment has confirmed that a trio of particles—a top-antitop quark pair and a W boson—occurs more frequently than expected in the wake of proton-proton collisions inside the Large Hadron Collider (LHC).

The process that creates these three particles post-impact is quite rare: Only one out of every 50,000 collisions at the LHC produces the trio, known as ttW. After popping into existence, top quarks and W bosons are short-lived and decay almost immediately, so the team identified ttW events based on the electrons and muons into which they decay.

Members of the ATLAS group at the Department of Energy's SLAC National Accelerator Laboratory have spent the last three years completing a complex analysis to measure the process, including developing novel methods to estimate and remove background and detector effects to maximize the accuracy and detail of the analysis of the measurement. The results will help researchers better test theories of elementary particle physics as well as help experimentalists studying other particle physics processes.

"The only measurements of ttW production come from the LHC—it is the first collider that can produce these types of events at a large enough rate to be measured," said Brendon Bullard, research associate at SLAC National Accelerator Laboratory and leader of this data analysis.
A puzzling excess

ATLAS first observed the ttW process in 2015 using data collected during the LHC's Run 1, which took place between 2010 and 2012. Subsequent measurements using a subset of data collected during Run 2 (2015-2018) suggested that ttW was cropping up more than predicted by the Standard Model of particle physics, which physicists use to describe the behavior of subatomic particles.

The most recent measurement using the full dataset collected by ATLAS during Run 2 has led to a more precise measurement of ttW, finding the total production rate to be about 20 percent higher than theoretical predictions. Fresh results from the CMS experiment corroborate this excess.
weatheriscool
Posts: 12967
Joined: Sun May 16, 2021 6:16 pm

Re: Physics News and Discussions

Post by weatheriscool »

User avatar
caltrek
Posts: 6509
Joined: Mon May 17, 2021 1:17 pm

Re: Physics News and Discussions

Post by caltrek »

Scientists Find Link Between Photosynthesis and ‘Fifth State of Matter’
May 3, 2023

Introduction:
(Eurekalert) Inside a lab, scientists marvel at a strange state that forms when they cool down atoms to nearly absolute zero. Outside their window, trees gather sunlight and turn them into new leaves. The two seem unrelated—but a new study from the University of Chicago suggests that these processes aren’t so different as they might appear on the surface.

The study, published in PRX Energy on April 28, found links at the atomic level between photosynthesis and exciton condensates—a strange state of physics that allows energy to flow frictionlessly through a material. The finding is scientifically intriguing and may suggest new ways to think about designing electronics, the authors said.

“As far as we know, these areas have never been connected before, so we found this very compelling and exciting,” said study co-author Prof. David Mazziotti.

Mazziotti’s lab specializes in modelling the complicated interactions of atoms and molecules as they display interesting properties. There’s no way to see these interactions with the naked eye, so computer modeling can give scientists a window into why the behavior happens—and can also provide a foundation for designing future technology.

In particular, Mazziotti and study co-authors Anna Schouten and LeeAnn Sager-Smith have been modelling what happens at the molecular level when photosynthesis occurs.

Read more here: https://www.eurekalert.org/news-releases/988142
Don't mourn, organize.

-Joe Hill
weatheriscool
Posts: 12967
Joined: Sun May 16, 2021 6:16 pm

Re: Physics News and Discussions

Post by weatheriscool »

Entangled quantum circuits further disprove Einstein's concept of local causality
https://phys.org/news/2023-05-entangled ... ncept.html
by Felix Würsten, ETH Zurich
A group of researchers led by Andreas Wallraff, Professor of Solid State Physics at ETH Zurich, has performed a loophole-free Bell test to disprove the concept of "local causality" formulated by Albert Einstein in response to quantum mechanics.

By showing that quantum mechanical objects that are far apart can be much more strongly correlated with each other than is possible in conventional systems, the researchers have provided further confirmation for quantum mechanics. What's special about this experiment is that the researchers were able for the first time to perform it using superconducting circuits, which are considered to be promising candidates for building powerful quantum computers.
An old dispute

A Bell test is based on an experimental setup that was initially devised as a thought experiment by British physicist John Bell in the 1960s. Bell wanted to settle a question that the greats of physics had already argued about in the 1930s: Are the predictions of quantum mechanics, which run completely counter to everyday intuition, correct, or do the conventional concepts of causality also apply in the atomic microcosm, as Albert Einstein believed?
weatheriscool
Posts: 12967
Joined: Sun May 16, 2021 6:16 pm

Re: Physics News and Discussions

Post by weatheriscool »

Supercomputing simulations spot electron orbital signatures
https://phys.org/news/2023-05-supercomp ... tures.html
by University of Texas at Austin
No one will ever be able to see a purely mathematical construct such as a perfect sphere. But now, scientists using supercomputer simulations and atomic resolution microscopes have imaged the signatures of electron orbitals, which are defined by mathematical equations of quantum mechanics and predict where an atom's electron is most likely to be.

Scientists at UT Austin, Princeton University, and ExxonMobil have directly observed the signatures of electron orbitals in two different transition-metal atoms, iron (Fe) and cobalt (Co) present in metal-phthalocyanines. Those signatures are apparent in the forces measured by atomic force microscopes, which often reflect the underlying orbitals and can be so interpreted.

Their study was published in March 2023 as an Editors' Highlight in the journal Nature Communications.

"Our collaborators at Princeton University found that despite Fe and Co being adjacent atoms on the periodic table, which implies similarity, the corresponding force spectra and their measured images show reproducible experimental differences," said study co-author James R. Chelikowsky, the W.A. "Tex" Moncrief, Jr. Chair of Computational Materials and professor in the Departments of Physics, Chemical Engineering, and Chemistry in the College of Natural Sciences at UT Austin. Chelikowsky also serves as the director of the Center for Computational Materials at the Oden Institute for Computational Engineering and Sciences.
weatheriscool
Posts: 12967
Joined: Sun May 16, 2021 6:16 pm

Re: Physics News and Discussions

Post by weatheriscool »

Telecom-wavelength quantum repeater node transmits quantum information over tens of kilometers
https://phys.org/news/2023-05-telecom-w ... -tens.html
by University of Innsbruck

A quarter century ago, theoretical physicists at the University of Innsbruck made the first proposal on how to transmit quantum information via quantum repeaters over long distances, which would open the door to the construction of a worldwide quantum information network.

Now, a new generation of Innsbruck researchers has built a quantum repeater node for the standard wavelength of telecommunication networks and transmitted quantum information over tens of kilometers. The study is published in the journal Physical Review Letters.

Quantum networks connect quantum processors or quantum sensors with each other. This allows tap-proof communication and high-performance distributed sensor networks. Between network nodes, quantum information is exchanged by photons that travel through optical waveguides. Over long distances, however, the likelihood of photons being lost increases dramatically.

As quantum information cannot simply be copied and amplified, 25 years ago Hans Briegel, Wolfgang Dür, Ignacio Cirac and Peter Zoller, then all at the University of Innsbruck, provided the blueprints for a quantum repeater. These featured light-matter entanglement sources and memories to create entanglement in independent network links that are connected between them by a so-called entanglement swap to finally distribute entanglement over long distances.
Even transmission over 800 kilometers possible
weatheriscool
Posts: 12967
Joined: Sun May 16, 2021 6:16 pm

Re: Physics News and Discussions

Post by weatheriscool »

Laser physicists directly observe first femtoseconds after photoinjection
https://phys.org/news/2023-05-laser-phy ... ction.html
by Ludwig Maximilian University of Munich
A laser pulse hits an electron in a solid. If it receives enough energy from the light wave, it can then move freely through a solid. This phenomenon, which scientists have been exploring since the beginnings of quantum mechanics, is called photoinjection. There are still open questions about how the relevant processes unfold in time.

Laser physicists of the attoworld team of LMU and the Max Planck Institute of Quantum Optics have now made a direct observation of how the optical properties of silicon and silicon dioxide evolve during the first few femtoseconds (millionths of a billionth of a second) after photoinjection with a strong laser pulse.

This physics of photoinjection is relatively simple when it comes to the photoelectric effect explained by Albert Einstein. Here, an electron absorbs a single photon that has enough energy to free the electron from a potential that constrains its motion. It gets more complicated when no photon in the light wave has enough energy to do so. In this case, bound electrons can become free by absorbing more than one photon at once or by quantum tunneling. These are nonlinear processes that are effective only when the electric field is strong, which means that only the central part of a laser pulse can drive them efficiently.
weatheriscool
Posts: 12967
Joined: Sun May 16, 2021 6:16 pm

Re: Physics News and Discussions

Post by weatheriscool »

First measurements of hypernuclei flow at the Relativistic Heavy Ion Collider
https://phys.org/news/2023-05-hypernucl ... lider.html
by Karen McNulty Walsh, Brookhaven National Laboratory
Physicists studying particle collisions at the Relativistic Heavy Ion Collider (RHIC) have published the first observation of directed flow of hypernuclei. These short-lived, rare nuclei contain at least one "hyperon" in addition to ordinary protons and neutrons.

Hyperons contain at least one "strange" quark in place of one of the up or down quarks that make up ordinary nucleons (the collective name for protons and neutrons). Such strange matter is thought to be abundant in the hearts of neutron stars, which are among the densest, most exotic objects in the universe. While blasting off to neutron stars to study this exotic matter is still the stuff of science fiction, particle collisions could give scientists insight into these celestial objects from a laboratory right here on Earth.
Post Reply