One of the biggest mysteries in astrophysics may be getting closer to an answer.

A new study published in Physical Review Letters suggests that the famous “Amaterasu particle” — one of the most energetic cosmic rays ever detected — may not have been a proton at all. Instead, it could have been an atomic nucleus heavier than iron.

Discovered in 2021 by the Telescope Array in Utah, the Amaterasu particle carried an astonishing 240 exa-electron volts (EeV) of energy. That’s roughly the same kinetic energy as a fast-moving tennis ball — compressed into a single atomic nucleus.

What puzzled scientists most was its apparent origin. The particle seemed to arrive from a vast cosmic void, a region of space with no obvious object capable of accelerating particles to such extreme energies.

Using detailed simulations, researchers found that ultraheavy nuclei may survive intergalactic journeys far better than protons. While lighter particles lose energy through interactions with background radiation, nuclei heavier than iron can retain much more of their original energy over cosmic distances.

If correct, the finding could help explain how particles like Amaterasu reach Earth from seemingly impossible locations.

Possible sources include:
• Collapsing massive stars
• Neutron star mergers
• Gamma-ray bursts

Future instruments such as AugerPrime and the proposed Global Cosmic Ray Observatory may reveal whether these ultraheavy nuclei are truly responsible for some of the most extreme particles ever observed.

Every ultrahigh-energy cosmic ray is a messenger from one of the universe’s most violent events. Understanding what these particles are made of may help us uncover where they come from — and how nature accelerates matter to energies far beyond anything humans can create.

What do you think is the most likely source of particles this extreme?

📄 Original paper · ScienceDaily summary

#CosmicRays #Astrophysics #ParticlePhysics #SpaceScience #NeutronStars

⚛️ Physicists May Have Finally Found Matter Made Mostly of Force

For nearly 50 years, physicists have searched for a bizarre particle predicted by quantum chromodynamics: the glueball.

Ordinary matter is built from quarks. Gluons are the particles that carry the strong nuclear force and “glue” quarks together inside protons and neutrons. But because gluons also interact with each other, theory predicts that they should be able to bind together — creating a particle with no ordinary valence quarks at its core.

Now the BESIII experiment in China says X(2370), a particle first detected in 2011, finally fits the bill. Using a dataset of roughly 10 billion J/ψ particles, researchers have gradually established its mass, spin and parity, unusual decay patterns, and now its flavor-singlet behavior. Taken together, the team argues that these properties are best explained if a pseudoscalar glueball is the dominant component of X(2370).

That distinction matters: scientists are not yet claiming X(2370) is a perfectly pure ball of gluons. Quantum particles can mix with other states, and the newest analysis is currently a preprint awaiting peer review. But independent physicists describe it as the strongest glueball evidence produced in decades.

If confirmed, it would be an extraordinary demonstration of one of QCD’s strangest predictions: the particles responsible for holding matter together can apparently bind together themselves.

Matter made mostly from the force that binds matter.

Physics occasionally writes its own headlines.

#Physics #ParticlePhysics #QuantumPhysics #QCD #Glueball #Science

https://english.ihep.cas.cn/nw/han/y26/202608/t20260804_1186878.html

💥 CERN Just Created a Tiny Version of the Early Universe

Physicists at the Large Hadron Collider have recreated the strange state of matter that filled the Universe shortly after the Big Bang — using atomic nuclei much smaller than researchers once thought would be sufficient.

The ALICE experiment smashed oxygen-16 and neon-20 nuclei together at enormous energies. The collisions produced evidence of collective hydrodynamic flow consistent with tiny droplets of quark–gluon plasma — the ultra-hot state in which quarks and gluons are no longer confined inside protons and neutrons.

But the most elegant part came afterward. The particles emerging from the miniature fireballs still carried information about the shape of the nuclei that created them. Oxygen produced a more rounded flow pattern, while neon generated a distinctly elongated signal — reflecting its predicted bowling-pin-like nuclear shape.

That means the same experiment can probe two extremes at once: matter as it behaved during the Universe’s first microseconds, and the tiny internal geometry of atomic nuclei.

Next, researchers want to go smaller still — potentially testing helium nuclei to discover just how tiny a system can be while still behaving like a liquid made of free quarks and gluons.

The Universe once existed in this state everywhere.

At CERN, it now survives for only a fraction of a fraction of a second.

#CERN #Physics #BigBang #QuarkGluonPlasma #ParticlePhysics #Science

https://journals.aps.org/prl/abstract/10.1103/gymp-vp87⁠

🌌 A Detector One Mile Underground May Have Seen Dark Matter

For decades, dark matter has been one of physics’ strangest certainties.

We can see its gravity shaping galaxies and the large-scale Universe — yet no one has ever directly detected the particle responsible for it.

Now the LUX-ZEPLIN experiment, buried nearly a mile underground in South Dakota, has recorded one unusually difficult-to-explain event.

LZ contains about 10 tonnes of ultrapure liquid xenon. Researchers watch for a dark-matter particle hitting a xenon nucleus and making it recoil. In 220 days of previously collected data, they found one event depositing about 248 keV of recoil energy — far more energetic than the simplest WIMP models normally predict.

The team spent months trying to explain it as radioactive contamination, neutrons or another known background process.

So far, none fits particularly well.

Under their background model, the result reaches 2.6 sigma, corresponding to roughly a 0.5% probability of obtaining such an event from known backgrounds. Particle physicists normally demand 5 sigma before claiming a discovery. And this entire result rests on exactly one event.

If it really was dark matter, the responsible particle would probably be unusually heavy — at least around 200 times the mass of a proton — and its interaction with ordinary matter would be more complicated than the simplest WIMP scenario.

The good news is that LZ is still collecting data.

If similar events begin appearing, the statistical significance should grow.

If they do not, today’s mysterious flash will probably become another extremely interesting piece of background noise.

For now, after decades of searching, dark matter may have knocked once.

Scientists are waiting to see whether it knocks again.

Status: preliminary candidate event; not a confirmed detection of dark matter.

#DarkMatter #Physics #Cosmology #ParticlePhysics #LUXZEPLIN #WIMP #Science

https://newscenter.lbl.gov/2026/09/01/lz-sees-surprising-result-in-search-for-dark-matter/

⚛️ Scientists Watched Matter “Appear” Inside a Quantum Computer

Pull two quarks apart and something deeply strange happens.

You never actually get two isolated quarks.

Instead, the energy binding them grows — almost as if an invisible string were being stretched between them. Eventually, storing more energy in that string becomes so expensive that nature takes another option:

it creates a new particle–antiparticle pair.

The string breaks.

This process, called string breaking, is fundamental to the strong nuclear force and probably played an important role in how matter evolved in the extremely hot early universe.

But calculating its real-time quantum dynamics is extraordinarily difficult.

So researchers from Duke University, the University of Maryland, Oxford, Caltech, Cornell and KU Leuven built a miniature analogue of the problem inside a quantum machine.

They programmed a chain of 13 trapped ytterbium ions to behave according to a simplified lattice gauge theory.

The ions were not literally turned into quarks.

Instead, their quantum states encoded the particles, fields and “string” connecting them — allowing researchers to watch the simulated system evolve with both spatial and temporal resolution.

And then the string broke.

New effective particle pairs appeared and propagated through the simulated system, reproducing the essential quantum dynamics physicists wanted to study.

But the experiment also produced a surprise.

The conventional expectation was that particle pairs would spontaneously appear throughout the string through a process related to the Schwinger mechanism.

Instead, the researchers observed pairs forming preferentially near the two ends of the string, then spreading inward.

Their calculations indicate this is a distinct, previously unobserved mechanism for dynamical string breaking.

This is not a simulation of the full Standard Model, and no real matter was created inside the computer. The experiment used a simplified 1+1-dimensional Z₂ gauge theory, and today’s classical computers can still reproduce a system this small.

The real prize comes later.

As quantum simulators grow, they could attack versions of these problems that conventional supercomputers cannot efficiently calculate — potentially letting physicists experimentally explore the quantum dynamics of particle collisions and conditions resembling the universe shortly after the Big Bang.

We built computers out of quantum mechanics.

Now we’re beginning to use them to ask quantum mechanics how the universe built matter.

#QuantumComputing #QuantumPhysics #ParticlePhysics #BigBang #Physics #Science

https://doi.org/10.1038/s41567-026-03422-0