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Archive for the ‘particle physics’ category: Page 155

Aug 5, 2023

Calculations reveal high-resolution view of quarks inside protons

Posted by in categories: nuclear energy, particle physics, supercomputing

A collaboration of nuclear theorists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, Argonne National Laboratory, Temple University, Adam Mickiewicz University of Poland, and the University of Bonn, Germany, has used supercomputers to predict the spatial distributions of charges, momentum, and other properties of “up” and “down” quarks within protons. The results, just published in Physical Review D, revealed key differences in the characteristics of the up and down quarks.

“This work is the first to leverage a new theoretical approach to obtain a high-resolution map of quarks within a ,” said Swagato Mukherjee of Brookhaven Lab’s nuclear theory group and a co-author on the paper. “Our calculations show that the up quark is more symmetrically distributed and spread over a smaller distance than the down quark. These differences imply that up and down quarks may make different contributions to the fundamental properties and structure of the proton, including its internal energy and spin.”

Co-author Martha Constantinou of Temple University noted, “Our calculations provide input for interpreting data from nuclear physics experiments exploring how quarks and the gluons that hold them together are distributed within the proton, giving rise to the proton’s overall properties.”

Aug 3, 2023

Standard Model Stays Strong for Leptons

Posted by in category: particle physics

Newly released data taken using the Belle II experiment at KEK in Japan and the LHCb experiment at CERN in Switzerland show no sign of a possible anomaly that researchers think could provide a route to overturning the standard model of particle physics [13].

According to the standard model, electrons, muons, and tau leptons should all behave identically when subjected to any of the fundamental forces of nature. Over a decade ago, researchers began questioning the validity of this assumption—known as lepton universality—when they observed high-energy particle decays that deviated from standard-model predictions. Specifically, the observations concerned the decay of B mesons into various leptons, with the experiments hinting that a few more tau leptons were being produced than expected. Excitement built among particle physicists, who hoped they were on the cusp of finding the long-sought standard-model violation that would uncover new physical phenomena. Hopes rose further as other experiments found hints of lepton-universality violations in the decay of B mesons into electrons and muons, but the signals remained too small to rule out experimental artifacts.

Then at the end of last year, hopes began to fade when the LHCb Collaboration released data for B-meson decays involving electrons and muons that exactly matched standard-model predictions [2, 3]. Now data from the Belle II Collaboration for a different B-meson decay involving electrons and muons dim those hopes further [1]. The study provides the most precise lepton-universality test yet in such decays. But researchers haven’t yet given up on leptons unlocking a door to new physics, says Belle II Collaboration member Henrik Junkerkalefeld of the University of Bonn, Germany. He notes that, although the results provide new constraints on the options for undiscovered physics, they don’t completely rule them all out.

Aug 2, 2023

Scientists believe they have discovered a portal to the Fifth Dimension

Posted by in categories: cosmology, particle physics

In a new study, scientists say that a particle that links to a fifth dimension can explain dark matter. (The previous article has been updated.)

Aug 2, 2023

Decoding the Mysteries of the “Wonder Material” Graphene Through Rainbow Scattering

Posted by in categories: materials, particle physics

New research uses protons to shine a light on the structure and imperfections of this two-dimensional wonder material.

Graphene is a two-dimensional wonder material that has been suggested for a wide range of applications in energy, technology, construction, and more since it was first isolated from graphite in 2004.

This single layer of carbon atoms is tough yet flexible, light but with high resistance, with graphene.

Aug 2, 2023

CERN Physicists Measure Higgs Boson’s Mass with Unprecedented Precision

Posted by in category: particle physics

The ATLAS and CMS collaborations at CENR’s Large Hadron Collider (LHC) have been making ever more precise measurements of the Higgs boson’s mass since the particle’s discovery.

The new ATLAS measurement combines two results: a new Higgs boson mass measurement based on an analysis of the particle’s decay into two high-energy photons (diphoton channel) and an earlier mass measurement based on a study of its decay into four leptons (four-lepton channel).

The new measurement in the diphoton channel, which combines analyses of the full ATLAS data sets from Runs 1 and 2 of the LHC, resulted in a mass of 125.22 billion electronvolts (GeV) with an uncertainty of only 0.14 GeV.

Aug 2, 2023

Quantum 101 Episode 5: Quantum Entanglement Explained

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

Quantum entanglement is one of the most intriguing and perplexing phenomena in quantum physics. It allows physicists to create connections between particles that seem to violate our understanding of space and time.

This video discusses what quantum entanglement really is, and the experiments that help us understand it. The results of these experiments have applications in new technologies that will forever change our world.

Continue reading “Quantum 101 Episode 5: Quantum Entanglement Explained” »

Aug 2, 2023

Giant alien-like virus structures with arms and tails found in the US

Posted by in categories: biotech/medical, education, particle physics

If there’s one thing the Covid pandemic taught us, it’s that viruses shouldn’t be underestimated.

People are, therefore, taking note after scientists discovered a whole new range of giant virus-like particles (VLP) that have taken on “previously unimaginable shapes and forms.”

The microscopic agents, resembling everything from stars to monsters, were found in just a few handfuls of forest soil.

Aug 1, 2023

Watching a Quantum System Thermalize

Posted by in categories: particle physics, quantum physics

Atoms trapped in a one-dimensional optical lattice can mimic how—in a basic quantum field theory—massive particles reach, or fail to reach, thermal equilibrium.

Aug 1, 2023

Measuring Decays with Rock Dating Implications

Posted by in categories: food, particle physics, space

Researchers revisit a neglected decay mode with implications for fundamental physics and for dating some of the oldest rocks on Earth and in the Solar System.

With a half-life of 1.25 billion years, potassium-40 does not decay often, but its decays have a big impact. As a relatively common isotope (0.012% of all potassium) of a very common metal (2.4% by mass of Earth’s crust), potassium-40 is one of the primary sources of radioactivity we encounter in daily life. Its decays are the primary source of argon-40, which makes up almost 1% of the atmosphere, and the copious amount of heat released from these decays threw off early estimates of the age of Earth made by Lord Kelvin. Potassium-40 is largely responsible for the meager radioactivity in our food (such as bananas), and it is a significant source of noise in some highly sensitive particle physics detectors. This isotope and its decay products are also useful tools in dating rocks and geological processes that go back to the earliest parts of Earth history. And yet some long-standing uncertainty surrounds these well-studied decays.

Aug 1, 2023

IceCube and NANOGrav open new windows onto the universe

Posted by in category: particle physics

Naoko Kurahashi Neilson was on a Zoom call when she saw it for the first time.

She and two PhD students—Mirco Hünnefeld of TU Dortmund University in Germany and Steve Sclafani of Drexel University in the United States—had received permission to review the results of their analysis. Using 10 years of data and 60,000 detections from the IceCube Neutrino Observatory, they were trying to map the emission of tiny, ghostly particles called neutrinos from the band of the Milky Way.

Kurahashi Neilson remembers the three of them staring at the image together. Slowly, they realized that they were, indeed, looking at the first-ever neutrino image of our galaxy.