. 24/7 Space News .
TIME AND SPACE
Physicists confirm hitch in proton structure
by Staff Writers
Newport News VA (SPX) Oct 20, 2022

File image of the Jefferson Lab's Continuous Electron Beam Accelerator Facility.

Nuclear physicists have confirmed that the current description of proton structure isn't all smooth sailing. A new precision measurement of the proton's electric polarizability performed at the U.S. Department of Energy's Thomas Jefferson National Accelerator Facility has revealed a bump in the data in probes of the proton's structure. Though widely thought to be a fluke when seen in earlier measurements, this new, more precise measurement has confirmed the presence of the anomaly and raises questions about its origin. The research has just been published in the journal Nature.

According to Ruonan Li, first author on the new paper and a graduate student at Temple University, measurements of the proton's electric polarizability reveal how susceptible the proton is to deformation, or stretching, in an electric field. Like size or charge, the electric polarizability is a fundamental property of proton structure.

What's more, a precision determination of the proton's electric polarizability can help bridge the different descriptions of the proton. Depending on how it is probed, a proton may appear as an opaque single particle or as a composite particle made of three quarks held together by the strong force.

"We want to understand the substructure of the proton. And we can imagine it like a model with the three balanced quarks in the middle," Li explained. "Now, put the proton in the electric field. The quarks have positive or negative charges. They will move in opposite directions. So, the electric polarizability reflects how easily the proton will be distorted by the electric field."

To probe this distortion, nuclear physicists used a process called virtual Compton scattering. It starts with a carefully controlled beam of energetic electrons from Jefferson Lab's Continuous Electron Beam Accelerator Facility, a DOE Office of Science user facility. The electrons are sent crashing into protons.

In virtual Compton scattering, electrons interact with other particles by emitting an energetic photon, or particle of light. The energy of the electron determines the energy of the photon it emits, which also determines how the photon interacts with other particles.

Lower energy photons may bounce off the surface of the proton, while more energetic photons will blast inside the proton to interact with one of its quarks. Theory predicts that when these photon-quark interactions are plotted at from lower to higher energies, they will form a smooth curve.

Nikos Sparveris, an associate professor of physics at Temple University and spokesperson for the experiment, said this simple picture didn't hold up to scrutiny. The measurements instead revealed an as-yet-unexplained bump.

"What we see is that there is some local enhancement to the magnitude of the polarizability. The polarizability decreases as the energy increases as expected. And, at some point, it appears to be coming temporarily up again before it will go down," he said. "Based on our current theoretical understanding, it should follow a very simple behavior. We see something that deviates from this simple behavior. And this is the fact that is puzzling us at the moment."

The theory predicts that the more energetic electrons are more directly probing the strong force as it binds the quarks together to make the proton. This weird spike in the stiffness that nuclear physicists have now confirmed in the proton's quarks signals that an unknown facet of the strong force may be at work.

"There is something that we're clearly missing at this point. The proton is the only composite building block in nature that is stable. So, if we are missing something fundamental there, it has implications or consequences for all of physics," Sparveris confirmed.

The physicists said that the next step is to further tease out the details of this anomaly and conduct precision probes to check for other points of deviation and to provide more information about the anomaly's source.

"We want to measure more points at various energies to present a clearer picture and to see if there is any further structure there," Li said.

Sparveris agreed.

"We also need to measure precisely the shape of this enhancement. The shape is important to further elucidating the theory," he said.

Research Report:Measured proton electromagnetic structure deviates from theoretical predictions


Related Links
Thomas Jefferson National Accelerator Facility
Understanding Time and Space


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


TIME AND SPACE
Tiny particles work together to do big things
Boston MA (SPX) Oct 17, 2022
Taking advantage of a phenomenon known as emergent behavior in the microscale, MIT engineers have designed simple microparticles that can collectively generate complex behavior, much the same way that a colony of ants can dig tunnels or collect food. Working together, the microparticles can generate a beating clock that oscillates at a very low frequency. These oscillations can then be harnessed to power tiny robotic devices, the researchers showed. "In addition to being interesting from a p ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

TIME AND SPACE
NASA Crew-4 astronauts safely splash down in Atlantic

Eagle-designed space drones target in-orbit construction

Crew-4 astronauts splash down after 170 days in space

World's first space tourist plans new flight to Moon with SpaceX

TIME AND SPACE
Celebrating committed orders for over 200 Astra spacecraft engines

Relativity Space to operate major rocket engine test facilities at NASA

Virgin Orbit and Luxembourg sign agreement to advance allied responsive space capabilities across Europe

The UK is about to have its first space launch

TIME AND SPACE
Packing up at the Canaima drill site: Sols 3626-3627

Life may have thrived on early Mars, until it drove climate change that caused its demise

Things that go bump in the night on Mars!

Sols 3621-3622: Planetary Power Puzzle

TIME AND SPACE
Mengtian space lab fueled ahead of upcoming launch

Tiangong space station marks key step in assembly

China begins search for fourth astronaut generation

China launches multiple satellites in back to back launches

TIME AND SPACE
Beyond Gravity to supply power electronics for Loft Orbital's satellites

Phase Four unveils game changing engine for LEO constellations

Viasat and Inmarsat will work with CMA to demonstrate customer benefits of proposed transaction

First Eurostar Neo satellite launched

TIME AND SPACE
Greening global economy brings dependence on critical minerals

Imerys to open lithium mine in France

Reprogrammable materials selectively self-assemble

Argonne lays the groundwork for its next-generation supercomputer

TIME AND SPACE
Blue Skies Space satellite will monitor how energy released by stars impacts exoplanet habitability

Heaviest element yet detected in an exoplanet atmosphere

Broccoli gas: A better way to find life in space

JPL developing more tools to help search for life in deep space

TIME AND SPACE
Mars and Jupiter moons meet

NASA studies origins of dwarf planet Haumea

NASA study suggests shallow lakes in Europa's icy crust could erupt

Sharpest Earth-based images of Europa and Ganymede reveal their icy landscape









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.