Physicists from the ATLAS Collaboration at CERN’s Large Hadron Collider (LHC) have found evidence of the Higgs boson decaying into a ‘virtual’ photon and a real photon, which in turn produces a pair of leptons.
The post CERN Physicists Find Evidence of One of Higgs Boson’s Rarest Decays appeared first on Sci.News: Breaking Science News.
Physicists from the ATLAS Collaboration at CERN’s Large Hadron Collider have confirmed that quantum entanglement -- the phenomenon Albert Einstein called ‘spooky action at a distance’ -- can survive in some of the most extreme conditions ever produced in a laboratory.
The post Entanglement Survives Violence of CERN’s Large Hadron Collider appeared first on Sci.News: Breaking Science News.
In a pair of papers published in the journal Physical Review Letters, a team of MIT physicists has shown that the neutrino laser -- a concept proposed just a year ago -- cannot actually be built, no matter how advanced the technology becomes.
The post Neutrino Laser is Physically and Fundamentally Impossible, Physicists Say appeared first on Sci.News: Breaking Science News.
Scientists from the Max-Planck-Institut für Kernphysik (MPIK) in Heidelberg, Germany, have announced the first successful detection of antineutrinos from an inactive nuclear reactor.
The research team behind the historic achievement said that detecting antineutrinos, which they described as “the most elusive particle in the Universe,” could improve monitoring, maintenance, safety, and security of nuclear reactors.
In a statement announcing the detection, the researchers point out that even when nuclear fission reactors are turned off, “the story inside the reactor core still has a great deal to tell.”
For example, the long-lived fission products inside nuclear reactors continue to decay for months, or in some cases, years after a reactor is no longer in use. This ongoing radioactive decay can produce what the team termed a “faint flux” of the most elusive particle in the universe: antineutrinos.
Because antineutrinos interact only extremely weakly with matter, they pass almost unhindered through the reactor vessel and surrounding shielding. In theory, the right equipment could detect this activity, offering insights into the reactor’s radioactive inner core.
Fortunately, for MPIK study leader Anthony Onillon and co-leader Thierry Lassere from the independent research group OMINA, also located at MPIK, there is an underground detector around 400 meters from two reactor cores, which were part of the region’s Chooz reactor in northern France.
Dubbed ‘Double Chooz,’ the detector contains over 30 cubic meters of liquid “scintillator.” According to the study authors, when antineutrinos interact with this material, a detectable flash of light is emitted.
“Antineutrinos interact only extremely rarely with matter,” Lasserre explained. “However, when one interacts within the Double-Chooz detector, a characteristic double-light signal is produced that can be distinguished from background events.”
To search for the weak antineutrino signal from the decaying Chooz nuclear reactor material, the research team evaluated recorded data from a 17.2-day period when both reactors were shut down. Because antineutrinos interact so rarely with matter, the researchers searched for the characteristic paired flashes produced when one underwent inverse beta decay inside the detector.
After scanning through the data, the team said they found evidence for roughly 100 “antineutrino candidate events” originating from within the reactors. This included signals from the cores and nearby spent-fuel cooling pools.
The researchers said the measured signal “agrees remarkably well” with simulations of the remaining fuel inventory and the decay of long-lived fission products.The team said this detection marks the first direct experimental validation of the antineutrino emissions predicted by the shutdown reactor models.
“With this new work, the experiment has achieved another first: observing the faint neutrino glow that remains after a reactor goes dark,” the research team explained.
When discussing the significance of the achievement, Dr. Onillon noted that previous efforts have primarily focused on operational nuclear reactors, where the antineutrino flux is much larger. Conversely, their detection was made under challenging conditions using methods perfected by the team.
“Detecting the tiny residual signal after shutdown required exceptionally low backgrounds and careful analysis techniques developed by the Double Chooz collaboration over many years,” the researcher explained.
When discussing the experiment’s practical applications, the team noted that the work provides researchers and regulators with “the first published benchmark” of the antineutrino glow coming from shutdown reactors and spent fuel pools. In theory, such detection could provide information on a reactor during both operational and maintenance phases.
“The results demonstrate that antineutrino detectors can probe nuclear reactors even during shutdown periods, opening new perspectives for reactor monitoring, nuclear safety, and safeguards,” they conclude, adding that such detections “may become relevant for independent verification of reactor status and spent-fuel inventories.”
The study “First measurement of neutrino emissions from spent nuclear fuel by the Double Chooz experiment” was published in Physical Review Letters.
Christopher Plain is a Science Fiction and Fantasy novelist and has spent the last six years as Associate News Editor and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him at christopher@thedebrief.org
A multi-institutional team of researchers led by University of Connecticut Professor Zhe Zhu has developed a method for measuring the dynamic, real-time activity of urban environments from space, which they are calling an “Urban Pulse.”
The research team behind the novel urban activity metric said that monitoring a city’s Urban Pulse could help mitigate uncontrolled urban sprawl or decay and enable environmentalists and urban planners to intervene before disasters become unavoidable.
Although environmentalists and urban planners have a wide range of tools to measure the activities within a city, Zhu notes that scientists have spent decades merely capturing the “outcome of urbanization,” such as a finished road or a newly completed home. However, the researcher and lead author of a study detailing the Urban Pulse methodology added that, even with all the current tools, “you don’t really see the dynamics within an urban area.”
According to a statement detailing the new approach, a city’s pulse is determined by all construction activity within it. Along with new construction, the metric includes repairs, infrastructure improvements, or expansion into previously undeveloped green spaces. When used correctly, the researchers said that it can help determine “if and where their city is not doing well.”
“This would allow (authorities) to be proactive rather than conducting a metaphorical autopsy after the decay of an area is evident,” the team explained.
To test their approach, the team evaluated the Urban Pulse of six cities: Seattle, Shenzhen, Lagos, Mumbai, Dubai, and Mexico City. This involved a deep examination of what the team termed “decades of dense time-series data” collected by NASA’s Harmonized Landsat and Sentinel-2 (HLS) satellites for physical transformations in an urban environment, such as new construction, measurable infrastructure improvements, and demolition.
Instead of analyzing each city’s changes manually, the team evaluated the above changes on what they called “the neighborhood level” using a deep-learning and time-series-analysis approach called CAPES, developed by former UConn postdoctoral researcher Ji Won Suh. The team said that, by observing these “high-frequency rhythms of development” from a broad ‘outer space’ perspective, their approach “bridges the gap between abstract urban theories and measurable, real-world data.”
After examining CAPES’ results, the team found several key markers within the Urban Pulse. For example, the view from space revealed that growth within cities is not smooth and steady. Instead, Zhu and colleagues said that development happens in “abrupt, intense, and episodic bursts of construction.”
CAPES also revealed that the rhythms of an urban environment are cyclical. For example, while a city may show relatively steady growth on a broader level, individual neighborhoods go through “dramatic boom-and-rest cycles” of expansion and dormancy that don’t appear to follow predictable annual seasons.
The third pattern revealed by measuring the six cities’ Urban Pulse from space was that cities are “asynchronous,” meaning a single city does not ‘beat’ in unison. The team noted that neighborhoods “pulse at completely different times.” When it functions properly, this “uncoordinated rhythm” helps prevent the city’s infrastructure and labor markets from “overheating.”
Unlike previous methods for tracking a city’s evolution, the team noted that their Urban Pulse approach can help researchers “visualize a city’s reaction to global shocks.” For example, the team said that their analysis captured “the exact moment the COVID-19 pandemic triggered a widespread, synchronized ‘cardiac arrest’ in urban development worldwide.”
However, their new tool also revealed what the researchers termed “profound inequalities” in how individual cities recovered from the dramatic halt to urban growth. For example, the team said that the Urban Pulse of Shenzhen revealed synchronized ‘dips’ in activity, followed almost immediately by “rapid, policy-driven rebounds.” However, the same Orban Pulse analysis showed that the reactions in Mumbai and Mexico City were much more “muted.”
“It’s like in human beings,” Zhu explained. “When you get a disease, it’s not going to show up exactly the same in different people.”
Although the Urban Pulse metric offers a tantalizing tool for academics, the team noted real-world benefits for global policymakers, urban planners, and environmentalists, adding that “it serves as an early warning system.”
“By monitoring the rhythm, rate, and amplitude of neighborhood pulses, governments can identify early signs of urban decay or unsustainable sprawl and intervene before crises become entrenched,” they explained.
The team also suggested that making Urban Pulse data publicly available could “revolutionize how everyday people interact with their cities.” For example, an urban family considering a move to a new city or a new part of their current city could track a target neighborhood’s pulse to spot early warning signs of decay or early indicators of positive-trending growth. The same data could help business owners plan new locations or expanded service routes, depending on the business profile and the local Urban Pulse trends.
“This is going to be a very impactful tool influencing not only top-down policy decisions from governments but also bottom-up decisions from everyday people navigating their cities,” Zhu explained.
In a recent study, “The Urban Pulse: Diagnosing the urbanization process as spiky, cyclical, and asynchronous” was published in the Proceedings of the National Academy of Sciences.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.
Login