Neutrino

Neutrinos are extremely lightweight and electrically neutral particles that rarely interact with ordinary matter. Due to these rare interactions, neutrinos can travel across space almost entirely unaffected, carrying information about highly energetic cosmological events, such as exploding stars or supermassive black holes.

Three years ago, a detector sitting on the floor of the Mediterranean Sea recorded a single subatomic particle carrying more energy than anything of its kind ever seen before. Where it came from has been a mystery ever since. Now, scientists working with the KM3NeT detector off the coast of Sicily think they may have found the culprit, a population of blazars, some of the most violent objects in the universe, each one powered by a supermassive black hole firing a jet of plasma directly toward Earth.

Learn how a deep-sea detector helped trace the most energetic neutrino ever detected to distant blazars.

Three years ago, in the waters of the Mediterranean Sea, the passage of an "ultra-energetic" cosmic neutrino was observed—the most energetic ever detected. The event drew international attention from the scientific community as well as from the media and the public, not least because the origin of this particle—whose energy exceeded that of previously observed neutrinos by more than an order of magnitude—is unknown.

An international team combining two major neutrino experiments has uncovered stronger evidence that neutrinos and antimatter don’t behave as perfect mirror images. That subtle difference may hold the key to why the universe didn’t vanish in a flash of self-destruction after the Big Bang.

The KM3NeT collaboration is a large research group involved in the operation of a neutrino telescope network in the deep Mediterranean Sea, with the aim of detecting high-energy neutrino events. These are rare and fleeting high-energy interactions between neutrinos, particles with an extremely low mass that are sometimes referred to as "ghost particles."

The name "IceCube" not only serves as the title of the experiment, but also describes its appearance. Embedded in the transparent ice of the South Pole, a three-dimensional grid of more than 5,000 extremely sensitive light sensors forms a giant cube with a volume of one cubic kilometer. This unique arrangement serves as an observatory for detecting neutrinos, the most difficult elementary particles to detect.

Since 2010, the IceCube Observatory at the Amundsen-Scott South Pole Station has been delivering groundbreaking measurements of high-energy cosmic neutrinos. It consists of many detectors embedded in a volume of Antarctic ice measuring approximately one cubic kilometer. IceCube has now been upgraded with new optical modules to enable it to measure lower-energy neutrinos as well. Researchers at the Karlsruhe Institute of Technology (KIT) made a significant contribution to this expansion.

The National Science Foundation's massive IceCube neutrino detector at the South Pole just got a major new upgrade, which promises to take the search for "ghost particles" to a new level.

Neutrinos are very small, neutral subatomic particles that rarely interact with ordinary matter and are thus sometimes referred to as ghost particles. There are three known types (i.e., flavors) of neutrinos, dubbed muon, electron and tau neutrinos.

A supercharged neutrino that smashed into our planet in 2023 may have been spit out by an exploding primordial black hole with a "dark charge." If true, this theory could lead to a definitive catalog of all subatomic particles and unveil the elusive identity of dark matter.

Ciaran O'Hare scribbles symbols using colored markers across his whiteboard like he's trying to solve a crime—or perhaps planning one. He bounces around the edges of the board, slowly filling it with sharp angles and curling letters. I watch on, and when he senses I'm losing track, he pauses intermittently, allowing my brain to catch up. Ciaran speaks with an easy to understand British inflection, but the language on the whiteboard might as well be hieroglyphics.

In 2023, a subatomic particle called a neutrino crashed into Earth with such a high amount of energy that it should have been impossible. In fact, there are no known sources anywhere in the universe capable of producing such energy—100,000 times more than the highest-energy particle ever produced by the Large Hadron Collider, the world's most powerful particle accelerator. However, a team of physicists at the University of Massachusetts Amherst recently hypothesized that something like this could happen when a special kind of black hole, called a "quasi-extremal primordial black hole," explodes.

Finding challenges the standard model of cosmology The post Interactions between dark matter and neutrinos could resolve a cosmic discrepancy appeared first on Physics World.

Primordial black holes could rewrite our understanding of dark matter and the early universe. A record-breaking detection at the bottom of the Mediterranean Sea has some physicists wondering if we just spotted one. The post Monster Neutrino Could Be a Messenger of Ancient Black Holes first appeared on Quanta Magazine

Astronomers found evidence that dark matter and neutrinos may interact, hinting at a "fundamental breakthrough" that challenges our understanding of how the universe evolved.

Neutrinos have kept scientists on their toes in the decades since they were discovered.

Every second, a trillion ghost particles stream through your body unnoticed, invisible messengers carrying secrets from the hearts of distant stars. Astrophysicists at the University of Copenhagen have now mapped exactly where these neutrinos originate across our Milky Way Galaxy and how many reach Earth, creating the most comprehensive picture yet of these elusive particles.

Scientists are a step closer to solving one of the universe's biggest mysteries as new research finds evidence that dark matter and neutrinos may be interacting, offering a rare window into the darkest recesses of the cosmos.

"WIMPs are still the leading candidate for dark matter, but billions of dollars of experiments have been done, only getting stronger and stronger upper limits, so alternative scenarios have to be considered."

Author(s): S. Abubakar et al. (The NOvA Collaboration)A decade of neutrino oscillation data leads to the most precise single-experiment measurement of the neutrino mass splitting between eigenstates 3 and 2. [Phys. Rev. Lett. 136, 011802] Published Thu Jan 08, 2026

With contributions from Brown faculty and students, the LUX-ZEPLIN experiment analyzed the largest dataset ever collected by a

The subatomic particles are incredibly numerous. About 1,000 neutrinos from stars other than the sun pass through a thumbnail every second.

They're called ghost particles for a reason. They're everywhere—trillions of them constantly stream through everything: our bodies, our planet, even the entire cosmos. These so-called neutrinos are elementary particles that are invisible, incredibly light, and interact only rarely with other matter.

Author(s): Pablo Martínez-Miravé and Irene TamborraThe authors estimate the total theoretical Galactic stellar neutrino flux, taking into account the latest results on stellar spatial distribution and star formation history. They estimate neutrino emission for a comprehensive range of stellar masses and lifetimes, thus obtaining a key baseline result for future neutrino detections of diverse origins. [Phys. Rev. D 113, 023014] Published Wed Jan 07, 2026

Scientists are a step closer to solving one of the universe's biggest mysteries as new research finds evidence that two of its least understood components may be interacting, offering a rare window into the darkest recesses of the cosmos.

Scientists are a step closer to solving one of the universe’s biggest mysteries as new research finds evidence that two of its least understood components may be interacting, offering a rare window into the darkest recesses of the cosmos.

"If this interaction between dark matter and neutrinos is confirmed, it would be a fundamental breakthrough."

Experimental particle physicists working at the MicroBooNE experiment at Fermilab National Accelerator Laboratory have found evidence against the existence of a "sterile" type of neutrino hypothesized to be responsible for previous experiments' anomalous results, as detailed in a paper published in Nature.

Neutrinos may be nearly invisible, but they play a starring role in the Universe. Long-standing anomalies had hinted at a mysterious fourth “sterile” neutrino, potentially rewriting the laws of physics. Using exquisitely precise measurements of tritium decay, the KATRIN experiment found no evidence for such a particle, sharply contradicting earlier claims. With more data and upgrades ahead, the hunt is far from over.

Author(s): C. Prévotat, Zh. Zhu, S. Koldobskiy, A. Neronov, D. Semikoz, and M. AhlersAs cosmic rays propagate through the Galaxy, they produce gamma rays and contribute to the gamma-ray background. The authors compute the expected gamma-ray background based on the observed cosmic ray flux. They show an overproduction of gamma-ray above 100 TeV, which they suggest is due to the rarity of 1 PeV cosmic-ray sources. Their work helps constrain the sources of high energy cosmic rays. [Phys. Rev. D 112, 123033] Published Fri Dec 19, 2025

Neutrinos are one of the most mysterious particles in the universe, often called “ghost particles” because they rarely

Australian researchers have played a central role in a landmark result from the LUX-ZEPLIN (LZ) experiment in South Dakota—the world's most sensitive dark matter detector. Today, scientists working on the experiment report they have further narrowed constraints on proposed dark matter particles. And, for the first time, the experiment has detected elusive neutrinos produced deep inside the sun.

Scientists have managed to observe solar neutrinos carrying out a rare atomic transformation deep underground, converting carbon-13 into nitrogen-13 inside the SNO+ detector. By tracking two faint flashes of light separated by several minutes, researchers confirmed one of the lowest-energy neutrino interactions ever detected.

There's a less than 5 percent chance that earlier anomalies can be explained by fourth neutrino "flavor."

Learn how a particle born in the sun’s core left a measurable flash of light two kilometers beneath Earth’s surface.

Fourth flavour not seen in beta-decay and oscillation The post Sterile neutrinos: KATRIN and MicroBooNE come up empty handed appeared first on Physics World.

Author(s): M. Abreu et al. ( SNO + Collaboration)The first evidence of 8 B solar neutrinos interacting with 13 C nuclei provides a test of the solar model as well as constitutes the lowest energy measurements of neutrino interactions on 13 C . [Phys. Rev. Lett. 135, 241803] Published Wed Dec 10, 2025

Avi Loeb links the strange behaviour of interstellar object 3I/ATLAS with the rise and fall of the sterile neutrino debate in modern physics.

Neutrinos are one of the most mysterious particles in the universe, often called "ghost particles" because they rarely interact with anything else. Trillions stream through our bodies every second, yet leave no trace. They are produced during nuclear reactions, including those that take place in the core of our sun.

Dark matter is an elusive type of matter that does not emit, reflect or absorb light, yet is estimated to account for most of the universe's mass. Over the past decades, many physicists worldwide have been trying to detect this type of matter or signals associated with its presence, employing various approaches and technologies.

Energy spectrum of elusive particles shows an intriguing bump, giant IceCube experiment reports

A new joint analysis from the NOvA and T2K experiments offers the most precise look yet at neutrino behavior, bringing scientists closer to understanding why the universe is made of matter.

Scientists have taken a major step toward solving a long-standing mystery in particle physics, by finding no sign of the particle many hoped would explain it.

Two papers challenged the existence of theorized particles called sterile neutrinos that might account for mysteries like the cosmos’s dark matter.

Neutrinos, though nearly invisible, are among the most numerous matter particles in the universe. The Standard Model recognizes three types, but the discovery of neutrino oscillations revealed they have mass and can change identity while propagating.

Two papers challenged the existence of theorized particles called sterile neutrinos that might account for mysteries like the cosmos’s dark matter.

Hidden beneath the hills of southern China, the JUNO observatory shows promise in solving neutrino mysteries

Deep underground in southern China, there is a 20,000-ton tank of liquid that can detect neutrinos. Named JUNO, the detector's first results are in — and they're very promising.

The observatory has also released its first results on the so-called solar neutrino tension The post Scientists in China celebrate the completion of the underground JUNO neutrino observatory appeared first on Physics World.

The world’s largest “ghost particle” detector, located in southern China’s Guangdong province, has shattered expectations in just two months. Initial results from the vast new Jiangmen Underground Neutrino Observatory (Juno) have shown a record level of precision, surpassing decades of cumulative data from other global experiments on neutrinos. The immediate success has confirmed that the detector is ready to tackle fundamental questions, potentially uncovering new laws of physics and solving...

A research team has conducted the first systematic search for optical counterparts to a neutrino "multiplet," a rare event in which multiple high-energy neutrinos are detected from the same direction within a short period. The event was observed by the IceCube Neutrino Observatory, a massive detector buried deep within the Antarctic ice.

Author(s): Jan Miśkiewicz, Maciej Konieczka, and Wojciech SatułaThis work describes the first calculation of a nuclear matrix element for the two-neutrino double-beta transition ( 2 ν β β 48 Ca → 48 Ti) within a recently developed theory framework, no-core configuration-interaction based on density-functional theory (DFT-NCCI). The authors build on a tested approach, and explicitly include nuclear deformation. A clever choice of the single-particle wave functions reduces the computational

When neutron stars collide, neutrinos can play a significant role in the outcome. Even more so when you take flavor mixing into account.

There is a limit to how big we can build particle colliders on Earth, whether that is because of limited space or limited economics. Since size is equivalent to energy output for particle colliders, that also means there's a limit to how energetic we can make them. And again, since high energies are required to test theories that go beyond the standard model (BSM) of particle physics, that means we will be limited in our ability to validate those theories until we build a collider big enough.

There is a limit to how big we can build particle colliders on Earth, whether that is because of limited space or limited economics. Since size is equivalent to energy output for particle colliders, that also means there’s a limit to how energetic we can make them. And again, since high energies are required to test theories that go Beyond the Standard Model (BSM) of particle physics, that means we will be limited in our ability to validate those theories until we build a collider big enough. But a team of scientists led by Yang Bai at the University of Wisconsin thinks they might have a better idea - use already existing neutrino detectors as a large scale particle collider that can reach energies way beyond what the LHC is capable of.

Scientists are searching for answers in the cosmic mystery of ghost particles known as neutrinos.

In a Physical Review Letters study, the HOLMES collaboration has achieved the most stringent upper bound on the effective electron neutrino mass ever obtained using a calorimetric approach, setting a limit of less than 27 eV/c² at 90% credibility.

In a new analysis, physicists provide the most precise picture yet of how neutrinos change ‘flavor’ as they

Very early on in our universe, when it was a seething hot cauldron of energy, particles made of

The origins of extremely high-energy particles that fill the universe—such as protons, electrons, and neutrinos—remain one of the longest-standing mysteries in modern astrophysics. A leading hypothesis suggests that "explosive transients," including massive stellar explosions (supernovae) and tidal disruption events (TDE) caused by stars being torn apart by black holes, could be the cosmic engines driving these energetic particles. Yet, this idea has never been rigorously tested.

By combining global experiments, physicists reveal the clearest view yet of how neutrinos change type as they move, offering clues to why the universe is made of matter.

Very early on in our universe, when it was a seething hot cauldron of energy, particles made of matter and antimatter bubbled into existence in equal proportions. For example, negatively charged electrons were created in the same numbers as their antimatter siblings, positively charged positrons. When the two particles combined, they canceled each other out.

Chinese researchers have tested a submersible vehicle designed to help them build one of the world’s largest neutrino observatories in the South China Sea – a facility that will study the ghostly subatomic particles that stream through the cosmos with barely a trace. The Subsea Precision Instrument Deployer with Elastic Releasing (Spider) uncoiled a 700 metre (2,300ft) string of 20 sensor balls at a depth of about 1,700 metres (5,580ft), according to the team from Shanghai Jiao Tong University’s...

University of Warwick physicists, as part of the Jiangmen Underground Neutrino Observatory (JUNO) in China, are celebrating helping

Author(s): W. Elbers et al. (DESI Collaboration)The new map of the Universe’s expansion history released by the DESI Collaboration offers hints at a breakdown of the standard model of cosmology. [Phys. Rev. D 112, 083513] Published Mon Oct 06, 2025

Physicists plan to test idea in the lab The post Radioactive BEC could form a ‘superradiant neutrino laser’ appeared first on Physics World.

Author(s): E. Aprile et al. (XENON Collaboration)Using advanced cryogenic distillation, the XENONnT experiment cuts radon levels in its 10-tonne liquid xenon detector to just 430 atoms per tonne, enabling ultrapure conditions for detecting faint dark matter signals. [Phys. Rev. X 15, 031079] Published Tue Sep 30, 2025

The last gasp of a primordial black hole may be the source of the highest-energy “ghost particle” detected

Author(s): B. K. Alpert et al.The HOLMES experiment demonstrates the capability of an approach that uses calorimetric measurement of electron capture decay of 163 Ho by placing a stringent upper bound on the electron neutrino mass. [Phys. Rev. Lett. 135, 141801] Published Mon Sep 29, 2025

If a new proposal by MIT physicists bears out, the recent detection of a record-setting neutrino could be the first evidence of elusive Hawking radiation.

The collision and merger of two neutron stars—the incredibly dense remnants of collapsed stars—are some of the most energetic events in the universe, producing a variety of signals that can be observed on Earth.

When two neutron stars collide, they unleash some of the most powerful forces in the universe, creating ripples in spacetime, showers of radiation, and even the building blocks of gold and platinum. Now, new simulations from Penn State and the University of Tennessee Knoxville reveal that elusive particles called neutrinos—able to shift between different “flavors”—play a crucial role in shaping what emerges from these cataclysmic events.

The Big Bang may have spawned these theoretical black holes, whose lives are thought to end in a burst of extremely energetic particles.

Cosmologically coupled black hole hypothesis also confirms that dark energy is evolving The post Unconventional approach to dark energy problem gives observed neutrino masses appeared first on Physics World.

If a new proposal by physicists bears out, the recent detection of a record-setting neutrino could be the first evidence of elusive Hawking radiation.

Author(s): Alexandra P. Klipfel and David I. KaiserBlack holes born in the early Universe could account for the recently observed ultrahigh-energy astrophysical neutrinos. [Phys. Rev. Lett. 135, 121003] Published Thu Sep 18, 2025

Author(s): Ryan WilkinsonBlack holes born in the early Universe could account for the recently observed ultrahigh-energy astrophysical neutrinos. [Physics 18, s124] Published Thu Sep 18, 2025

The last gasp of a primordial black hole may be the source of the highest-energy "ghost particle" detected to date, a new MIT study proposes.

A recent Physical Review Letters publication presents a thorough analysis of MicroBooNE detector data, investigating the anomalous surplus of neutrino-like events detected by the preceding MiniBooNE experiment.

Neutrinos are one of the most enigmatic particles in the standard model. The main reason is that they're so hard to detect. Despite the fact that 400 trillion of them created in the sun are passing through a person's body every second, they rarely interact with normal matter, making understanding anything about them difficult. To help solve their mysteries, a new neutrino detector in China recently started collecting data, and hopes to provide insight on between forty and sixty neutrinos a day for the next ten years.

Neutrinos are one of the most enigmatic particles in the standard model. The main reason is that they’re so hard to detect. Despite the fact that 400 trillion of them created in the Sun are passing through a person’s body every second, they rarely interact with normal matter, making understanding anything about them difficult. To help solve their mysteries, a new neutrino detector in China recently started collecting data, and hopes to provide insight on between forty and sixty neutrinos a day for the next ten years.

Author(s): B. J. P. Jones and J. A. FormaggioA Bose-Einstein condensate of radioactive atoms could turn into a source of intense, coherent, and directional neutrino beams, according to a theoretical proposal. [Phys. Rev. Lett. 135, 111801] Published Mon Sep 08, 2025

Author(s): Kyle G. LeachA Bose-Einstein condensate of radioactive atoms could turn into a source of intense, coherent, and directional neutrino beams, according to a theoretical proposal. [Physics 18, 157] Published Mon Sep 08, 2025

The subatomic particles called neutrinos are famously elusive. But an unconventional trick could make a laser beam of the aloof particles.

At any given moment, trillions of particles called neutrinos are streaming through our bodies and every material in our surroundings, without noticeable effect. Smaller than electrons and lighter than photons, these ghostly entities are the most abundant particles with mass in the universe.

These are exciting times to explore the largest unanswered questions in physics thanks to high-tech experiments and very