High Energy Scattering Data

Messenger from the dark side: Dark matter may interact with normal matter via a hypothetical particle known as a dark photon. (Courtesy: Shutterstock/80's Child)



A new analysis conducted by an international team of physicists suggests that dark photons – hypothetical particles that carry forces associated with dark matter – could explain certain data from high-energy scattering experiments. The analysis, which was led by,  Nicholas Hunt-Smith and colleagues at the University of Adelaide, Australia, could lead to new insights into the nature of dark matter, which remains a mystery even though standard models of cosmology suggest it makes up around 85% of the universe’s mass.

Dark matter gets its name because it does not absorb, reflect or emit electromagnetic radiation. This makes it extremely difficult to detect in the laboratory, and so far all attempts at doing so have come up empty-handed. “No particle beyond the Standard Model, which describes all the matter with which we are familiar, has ever been seen,” says Anthony Thomas, a physicist at Adelaide and a co-author of the analysis, which is published in the Journal of High Energy Physics. “We have no idea what dark matter is, although it seems likely to be [a] beyond standard model particle (or particles).”
The dark photon hypothesis

Though dark matter is poorly understood, it is nevertheless the leading explanation for why galaxies rotate faster than they should, given the amount of visible matter they contain. But although we can observe dark matter interacting with the universe, the mechanism for these interactions is unclear. According to Carlos Wagner, a particle physicist in the High Energy Physics (HEP) division of Argonne National Laboratory and a professor at the University of Chicago and the Enrico Fermi Institute, dark photons are one possibility.   READ MORE...

Smallest Known Way to Guide Light

Scientists at the University of Chicago found a glass crystal just a few atoms thick can trap and carry light—and could be used for applications. The material is visible as the thin line in the center of the plastic, held by study co-author Hanyu Hong. Credit: Jean Lachat



2D optical waveguides could pave the way for innovative technology.

Channeling light from one location to another is the backbone of our modern world. Across deep oceans and vast continents, fiber optic cables transport light containing data ranging from YouTube clips to banking transmissions—all within fibers as thin as a strand of hair.

University of Chicago Prof. Jiwoong Park, however, wondered what would happen if you made even thinner and flatter strands—in effect, so thin that they’re actually 2D instead of 3D. What would happen to the light?

Through a series of innovative experiments, he and his team found that a sheet of glass crystal just a few atoms thick could trap and carry light. Not only that, but it was surprisingly efficient and could travel relatively long distances—up to a centimeter, which is very far in the world of light-based computing.

The research, recently published in the journal Science, demonstrates what are essentially 2D photonic circuits, and could open paths to new technology.

“We were utterly surprised by how powerful this super-thin crystal is; not only can it hold energy, but deliver it a thousand times further than anyone has seen in similar systems,” said lead study author Jiwoong Park, a professor and chair of chemistry and faculty member of the James Franck Institute and Pritzker School of Molecular Engineering. “The trapped light also behaved like it is traveling in a 2D space.”

Guiding light
The newly invented system is a way to guide light—known as a waveguide—that is essentially two-dimensional. In tests, the researchers found they could use extremely tiny prisms, lenses, and switches to guide the path of the light along a chip—all the ingredients for circuits and computations.  READ MORE...

Photosynthesis and Fifth State of Matter

A University of Chicago study 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.




University of Chicago scientists hope ‘islands’ of exciton condensation may point way to new discoveries.

Scientists at the University of Chicago have found a connection between photosynthesis and exciton condensates, a state of physics that allows energy to flow without friction. This surprising finding, typically associated with materials well below room temperature, may inform future electronic design and help unravel complex atomic interactions.


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.  READ MORE...

Cancer Drug Kills Cancer Cells

Although interleukin-12 caused adverse side effects, researchers have long hypothesized that it 

would be a potent cancer treatment. A new form of the molecule has been created by Pritzker 

Molecular Engineering researchers that does not activate until it enters a tumor, 

where it kills cancer cells.

Numerous cancer treatments are notoriously harsh on the body; they assault healthy cells simultaneously with tumor cells and result in a wide range of side effects. 

The Pritzker School of Molecular Engineering (PME) at the University of Chicago has now developed a strategy to prevent one potential cancer drug from causing such damage. Interleukin-12 has been modified by scientists into a new, “masked” form that is only activated when it comes into contact with a tumor. 

The study on the molecule, also known as IL-12, was published in the journal Nature Biomedical Engineering.

“Our research shows that this masked version of IL-12 is much safer for the body, but it possesses the same anti-tumor efficacy as the original,” said Aslan Mansurov, a postdoctoral research fellow and first author of the new paper. 

He carried out the IL-12 engineering work with Jeffrey Hubbell, the Eugene Bell Professor in Tissue Engineering, who co-leads PME’s Immunoengineering research theme with professor Melody Swartz.

Researchers have discovered that IL-12 strongly activates lymphocytes, which are immune cells with the ability to kill tumor cells. Early IL-12 clinical studies, however, were stopped in the 1990s due to the patients’ harsh, toxic side effects. 

The same immune activation that set off a series of events that killed the cancer cells also caused significant inflammation throughout the body. The study of IL-12 was discontinued, at least in its natural form.


However, Mansurov, Hubbell, Swartz, and others came up with a plan to revive the potential of IL-12. What if the medication could pass through the body without triggering the immune system? T

They created a “masked” molecule with a cap covering the region of IL-12 that typically binds immune cells. Only tumor-associated proteases, a collection of molecular scissors located close to tumors to aid them in destroying the good tissue around them, can cut off the cap. 

The IL-12 becomes active and is then able to activate an immune response against the tumor when the proteases remove the cap.  READ MORE...

Hybrid Atomic Quantum Computers

Left: A hybrid array of cesium atoms (yellow) and rubidium atoms (blue). Right: The customizability of the researchers' technique enables them to place the atoms anywhere, allowing them to create this image of Chicago landmarks Willis Tower and the Cloud Gate. The scale bar in both images is 10 micrometers. Credit: Hannes Bernien

Qubits, the building blocks of quantum computers, can be made from many different technologies. One way to make a qubit is to trap a single neutral atom in place using a focused laser, a technique that won the Nobel Prize in 2018.


But to make a quantum computer out of neutral atom qubits, many individual atoms must be trapped in place by many laser beams. So far, these arrays have only been constructed from atoms of a single element, out of concern that making an array out of two elements would be prohibitively complex.

But for the first time, University of Chicago researchers have created a hybrid array of neutral atoms from two different elements, significantly broadening the system's potential applications in quantum technology. The results were funded in part by the NSF Quantum Leap Challenge Institute Hybrid Quantum Architectures and Networks (HQAN), and published in Physical Review X.

"There have been many examples of quantum technology that have taken a hybrid approach," said Hannes Bernien, lead researcher of the project and assistant professor in University of Chicago's Pritzker School of Molecular Engineering. "But they have not been developed yet for these neutral atom platforms. We are very excited to see that our results have triggered a very positive response from the community, and that new protocols using our hybrid techniques are being developed."

Double the potential
While manmade qubits such as superconducting circuits require quality control to stay perfectly consistent, neutral atoms made from a single element all have exactly the same properties, making them ideal, consistent candidates for qubits.

But since every atom in the array has the same properties, it's extremely difficult to measure a single atom without disturbing its neighbors—they're all on the same frequency, so to speak.  READ MORE...

Miserable Liberals

Stephen Moore, Replacing former President Donald Trump with President Joe Biden was supposed to bring joy to the land from sea to sea.

We were going to be a united people at last. Every problem known to man would get solved by cradle-to-grave government. Biden was even going to save us from the rise of the oceans.

I’m the kind of guy
Who never used to cry
The world is treatin’ me bad
Misery

— The Beatles

But just the opposite: A survey by the University of Chicago found that record percentages of people in 2021 described themselves as “unhappy.”

For most of the past 50 years, about 1 in 10 people have described themselves as unhappy. In 2021, 1 in 4 say they are unhappy. Typically, almost 1 in 3 say they are “very happy,” and now less than 1 in 5 do. The happiness index is falling like a stone. People are depressed.

Gee, I wonder why the public is so glum all of a sudden.

Let me count the ways. First, there is isolation and loneliness from lockdowns, stay-at-home orders and travel restrictions. Then there is out-of-control crime and a significant rise in business failures (from lockdowns), both clearly associated with depression. People are still worried about their health two years into the pandemic that Biden promised to shut down. The border is out of control.

Then there is the financial stress on families from everything being more expensive. Children are depressed because schools are still doing remote learning or they are stuck wearing masks for eight hours a day. The “woke” movement has people feeling like they are tied inside a social straitjacket. Nothing is funny anymore. Don’t you dare say an off-color joke or you will be banished.

People are afraid to laugh at anything for fear of offending someone somewhere. When was the last time you saw a funny movie?

But here’s what’s most interesting about the results of the happiness survey. The people with the most significant happiness deficiencies are Democratic voters. Liberals are miserable. Only 1 in 6 Democratic voters say they are “very happy.” Almost twice as many Republicans say they are “very happy.”

Why is that? I have several admittedly unproven hypotheses. I will toss them out, and readers can decide for themselves if they agree or disagree.

First, liberals are much less religious, patriotic and interested in getting married and having children than conservatives. It’s a Grand Canyon-sized division between liberals and conservatives. I’d venture to say that the love of country, God and family make people happy.

If you don’t believe in these things, you will likely believe in false idols, such as big government, as your savior. That’s hardly a path to happiness.

Liberals are less likely to be working and more likely to be on government assistance. But every study shows that work is highly associated with happiness. Giving a person a fish rather than teaching a person to fish leads to very different life satisfaction outcomes.  READ MORE...

Defying Newton's Third Law

Newton’s third law tells us that for every action, there’s an equal reaction going the opposite way. It’s been reassuring us for 400 years, explaining why we don’t fall through the floor (the floor pushes up on us too), and why paddling a boat makes it glide through water. 

When a system is in equilibrium, no energy goes in or out and such reciprocity is the rule. Mathematically, these systems are elegantly described with statistical mechanics, the branch of physics that explains how collections of objects behave. This allows researchers to fully model the conditions that give rise to phase transitions in matter, when one state of matter transforms into another, such as when water freezes.

But many systems exist and persist far from equilibrium. Perhaps the most glaring example is life itself. We’re kept out of equilibrium by our metabolism, which converts matter into energy. A human body that settles into equilibrium is a dead body.

In such systems, Newton’s third law becomes moot. Equal-and-opposite falls apart. “Imagine two particles,” said Vincenzo Vitelli, a condensed matter theorist at the University of Chicago, “where A interacts with B in a different way than how B interacts with A.” Such nonreciprocal relationships show up in systems like neuron networks and particles in fluids and even, on a larger scale, in social groups. Predators eat prey, for example, but prey doesn’t eat its predators.

For these unruly systems, statistical mechanics falls short in representing phase transitions. Out of equilibrium, nonreciprocity dominates. Flocking birds show how easily the law is broken: Because they can’t see behind them, individuals change their flight patterns in response to the birds ahead of them. 

So bird A doesn’t interact with bird B in the same way that bird B interacts with bird A; it’s not reciprocal. Cars barreling down a highway or stuck in traffic are similarly nonreciprocal. Engineers and physicists who work with metamaterials — which get their properties from structure, rather than substance — have harnessed nonreciprocal elements to design acoustic, quantum and mechanical devices.  READ MORE...

Profound Implications

Peering down a row of magnets leading to the particle storage ring at Fermilab’s Muon g-2 experiment. The results have theoretical physicists around the world frantically working through ideas for explanations. Credit: Photo by Cindy Arnold/Fermilab

The news that muons have a little extra wiggle in their step sent word buzzing around the world this spring.

The Muon g-2 experiment hosted at Fermi National Accelerator Laboratory announced on April 7 that they had measured a particle called a muon behaving slightly differently than predicted in their giant accelerator. It was the first unexpected news in particle physics in years.

Everyone’s excited, but few more so than the scientists whose job it is to spitball theories about how the universe is put together. For these theorists, the announcement has them dusting off old theories and speculating on new ones.

“To a lot of us, it looks like and smells like new physics,” said Prof. Dan Hooper. “It may be that one day we look back at this and this result is seen as a herald.”

Gordan Krnjaic, a fellow theoretical physicist, agreed: “It’s a great time to be a speculator.”

The two scientists are affiliated with the University of Chicago and Fermilab; neither worked directly on the Muon g-2 experiment, but both were elated by the results. To them, these findings could be a clue that points the way to unraveling the last mysteries of particle physics—and with it, our understanding of the universe as a whole.

The Muon g-2 ring sits in its detector hall amidst electronics racks, the muon beamline, and other equipment. This impressive experiment operates at negative 450 degrees Fahrenheit and studies the precession, or “wobble,” of particles called muons as they travel through the magnetic field. Credit: Reidar Hahn/Fermilab  Setting the Standard

The problem was that everything was going as expected.

Based on century-old experiments and theories going back to the days of Albert Einstein’s early research, scientists have sketched out a theory of how the universe—from its smallest particles to its largest forces—is put together. This explanation, called the Standard Model, does a pretty good job of connecting the dots. But there are a few holes—things we’ve seen in the universe that aren’t accounted for in the model, like dark matter.

No problem, scientists thought. They built bigger experiments, like the Large Hadron Collider in Europe, to investigate the most fundamental properties of particles, sure that this would yield clues. But even as they looked more deeply, nothing they found seemed out of step with the Standard Model. Without new avenues to investigate, scientists had no idea where and how to look for explanations for the discrepancies like dark matter.

Then, finally, the Muon g-2 experiment results came in from Fermilab (which is affiliated with the University of Chicago). The experiment reported a tiny difference between how muons should behave according to the Standard Model, and what they were actually doing inside the giant accelerator.  TO READ ENTIRE ARTICLE, CLICK HERE...