particle physics Archives

November 16, 2024November 16, 2024 by Alan Boyle

America’s Particle Physics Plan Spans the Globe — and the Cosmos

Illustration showing subatomic particles and galaxies in collision — Particle physics experiments address mysteries at subatomic and astronomical levels. (Illustration by Olena Shmahalo for U.S. Particle Physics)

RALEIGH, N.C. — Particle physicist Hitoshi Murayama admits that he used to worry about being known as the “most hated man” in his field of science. But the good news is that now he can joke about it.

Last year, the Berkeley professor chaired the Particle Physics Project Prioritization Panel, or P5, which drew up a list of multimillion-dollar physics experiments that should move ahead over the next 10 years. The list focused on phenomena ranging from subatomic smash-ups to cosmic inflation. At the same time, the panel also had to decide which projects would have to be left behind for budgetary reasons, which could have turned Murayama into the Dr. No of physics.

Although Murayama has some regrets about the projects that were put off, he’s satisfied with how the process turned out. Now he’s just hoping that the federal government will follow through on the P5’s top priorities.

June 22, 2024June 22, 2024 by Laurence Tognetti

Do Protons Decay? The Answer Might be on the Moon

Model of proton decay. (Credit: Wikipedia/Cjean42; Creative Commons Attribution-Share Alike 3.0 Unported license.)

Does proton decay exist and how do we search for it? This is what a recently submitted study hopes to address as a team of international researchers investigate a concept of using samples from the Moon to search for evidence of proton decay, which remains a hypothetical type of particle decay that has yet to be observed and continues to elude particle physicists. This study holds the potential to help solve one of the longstanding mysteries in all of physics, as it could enable new studies into deep-level and the laws of nature, overall.

February 12, 2024February 12, 2024 by Mark Thompson

CERN Wants to Build an Enormous New Atom Smasher: the Future Circular Collider

One of my favourite science and engineering facts is that an underground river was frozen to enable the Large Hadron Collider (LHC) to be built! On its completion, it helped to complete the proverbial jigsaw of the Standard Model with is last piece, the Higgs Boson. But that’s about as far as it has got with no other exciting leaps forward in uniting gravity and quantum physics. Plans are now afoot to build a new collider that will be three times longer than the LHC and it will be capable of smashing particles together with significantly more energy.

December 20, 2023December 21, 2023 by Paul M. Sutter

The Strangest Coincidence in Physics: The AdS/CFT Correspondence

The west limb of the Sun imaged by NuSTAR and SDO shows areas of high-energy x-rays above particularly active regions (NASA/JPL-Caltech/GSFC)

Attempts to turn string theory into a workable theory of nature have led to the potential conclusion that our universe is a hologram: that what we perceive as three spatial dimensions is actually composed of only two. The greatest realization of this hologram-led program is a proposal that goes by the awkward and clunky name of the AdS/CFT correspondence, first proposed by string theorist Juan Maldacena in the late 1990’s.

November 21, 2023November 21, 2023 by Brian Koberlein

CERN Has Joined the Search for Dark Photons

Illustration of two types of long-lived particles decaying into a pair of muons. Credit: CMS/CERN

In the search for dark matter particles, there are two main approaches. The first is to look for particles that happen to decay naturally as they pass by. This typically involves neutrino observatories such as IceCube where a dark matter particle particle colliding with a nuclei might trigger a faint burst of light. So far this has turned up nothing. The second approach is to slam particles together in a particle accelerator. This approach has also failed to find dark matter particles, but there have been enough interesting hints that CERN is having a go. Their latest run is looking for what are known as dark photons.

June 17, 2023June 11, 2023 by Paul M. Sutter

The Best Particle Collider in the World? The Sun

A look inside ALICE at the Large Hadron Collider. ALICE is one of the LHC's four particle detectors. Image: CERN/LHC

Recently astronomers caught a strange mystery: extremely high-energy particles spitting out of the surface of the Sun when it was relatively calm. Now a team of theorists have proposed a simple solution to the mystery. We just have to look a little bit under the surface.

November 29, 2022November 29, 2022 by Allen Versfeld

The Technique for Detecting Meteors Could be Used to Find Dark Matter Particles Entering the Atmosphere

A perseid meteor, streaking across the night sky. Image credit: Andreas Möller — A Perseid meteor streaks across the sky, leaving a glowing ionized trail. Image credit: Andreas Möller, licensed under

Researchers from Ohio State University have come up with a novel method to detect dark matter, based on existing meteor-detecting technology. By using ground-based radar to search for ionization trails, similar to those produced by meteors as they streak through the air, they hope to use the Earth’s atmosphere as a super-sized particle detector. The results of experiments using this technique would help researchers to narrow down the range of possible characteristics of dark matter particles.

November 4, 2022November 4, 2022 by Evan Gough

IceCube Senses Neutrinos Streaming From an Active Galaxy 47 Million Light-Years Away

This is a Hubble Space Telescope image of the Messier 77 spiral galaxy. Scientists working with the IceCube Neutrino Observatory detected neutrinos emanating from the galaxy's core. Image Credit: By NASA, ESA & A. van der Hoeven - http://www.spacetelescope.org/news/heic1305/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=25328266

Researchers using the IceCube Neutrino Observatory have detected neutrinos emanating from the energetic core of an active galaxy millions of light-years away. Neutrinos are difficult to detect, and finding them originating from the galaxy is a significant development. What does the discovery mean?

July 5, 2022July 5, 2022 by Alan Boyle

LHC Scientists Find Three Exotic Particles — and Start Hunting for More

Pentaquark structure — The new pentaquark, illustrated here as a pair of standard hadrons loosely bound in a molecule-like structure, is made up of a charm quark and a charm antiquark and an up, a down and a strange quark (CERN Illustration)

Physicists say they’ve found evidence in data from Europe’s Large Hadron Collider for three never-before-seen combinations of quarks, just as the world’s largest particle-smasher is beginning a new round of high-energy experiments.

The three exotic types of particles — which include two four-quark combinations, known as tetraquarks, plus a five-quark unit called a pentaquark — are totally consistent with the Standard Model, the decades-old theory that describes the structure of atoms.

In contrast, scientists hope that the LHC’s current run will turn up evidence of physics that goes beyond the Standard Model to explain the nature of mysterious phenomena such as dark matter. Such evidence could point to new arrays of subatomic particles, or even extra dimensions in our universe.

April 25, 2022April 25, 2022 by Alan Boyle

Large Hadron Collider Restarts, Shooting Protons at Record Energy Levels

LHC tunnel — A ring of magnets runs through the Large Hadron Collider's 17-mile-round (27-kilometer-round) tunnel. (CERN Photo / Samuel Joseph Herzog)

Europe’s Large Hadron Collider has started up its proton beams again at unprecedented energy levels after going through a three-year shutdown for maintenance and upgrades.

It only took a couple of days of tweaking for the pilot streams of protons to reach a record energy level of 6.8 tera electronvolts, or TeV. That exceeds the previous record of 6.5 TeV, which was set by the LHC in 2015 at the start of the particle collider’s second run.

The new level comes “very close to the design energy of the LHC, which is 7 TeV,” Jörg Wenninger, head of the LHC beam operation section and LHC machine coordinator at CERN, said today in a video announcing the milestone.

When the collider at the French-Swiss border resumes honest-to-goodness science operations, probably within a few months, the international LHC team plans to address mysteries that could send theories of physics in new directions.

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