Una nueva doctrina militar detalla capacidades tanto ofensivas como defensivas para asegurar su superioridad orbital
The CMS collaboration at CERN has observed an unexpected feature in data produced by the Large Hadron Collider (LHC), which could point to the existence of the smallest composite particle yet observed. The result, reported at the Rencontres de Moriond conference in the Italian Alps this week, suggests that top quarks – the heaviest and shortest lived of all the elementary particles – can momentarily pair up with their antimatter counterparts to produce an object called toponium. Other explanations cannot be ruled out, however, as the existence of toponium was thought too difficult to verify at the LHC, and the result will need to be further scrutinised by CMS’s sister experiment, ATLAS.
High-energy collisions between protons at the LHC routinely produce top quark–antiquark pairs (tt-bar). Measuring the probability, or cross section, of tt-bar production is both an important test of the Standard Model of particle physics and a powerful way to search for the existence of new particles that are not described by the 50-year-old theory. Many of the open questions in particle physics, such as the nature of dark matter, motivate the search for new particles that may be too heavy to have been produced in experiments so far.
CMS researchers were analysing a large sample of tt-bar production data collected in 2016–2018 to search for new types of Higgs bosons when they spotted something unusual. Additional Higgs-like particles are predicted in many extensions of the Standard Model. If they exist, such particles are expected to interact most strongly with the singularly massive top quark, which weighs in at 184 times the mass of the proton. And if they are massive enough to decay into a top quark–antiquark pair, this should dominate the way they decay inside detectors, with the two massive quarks splintering into “jets” of particles.
A new international study reveals a possible connection between GLP1 receptor agonists—used in drugs like Ozempic—and increased risk of depression and suicidal ideation, especially in people with low dopamine function.
Understanding and treating brain disorders such as tremor, imbalance, and speech impairments requires deep knowledge of the cerebellum, a part of the brain that’s crucial for making accurate movements.
Scientists have long been able to eavesdrop on and record the electrical signals transmitted by neurons (brain cells) in the cerebellum, allowing them to observe the signals entering and exiting this region. But the computations that the brain performs between the input and output have been largely a mystery.
However, that is now changing. A team of researchers, including those from Baylor College of Medicine, have created an artificial intelligence tool that can identify the type of neuron producing electrical signals recorded from the cerebellum during behavior, allowing a new understanding of how the cerebellum works.
Every day, people are constantly learning and forming new memories. When you pick up a new hobby, try a recipe a friend recommended or read the latest world news, your brain stores many of these memories for years or decades.
But how does your brain achieve this incredible feat?
In our newly published research in the journal Science, we have identified some of the “rules” the brain uses to learn.
Traditionally, magnetic materials have been divided into two main categories: ferromagnets and antiferromagnets. Over the past few years, however, physicists have uncovered the existence of altermagnets, a new type of magnetic material that exhibits features of both antiferromagnets and ferromagnets.
Altermagnets are magnetic materials that have no net magnetization (i.e., their atomic magnetic moments cancel each other out), like antiferromagnets. Yet they also break spin degeneracy (i.e., the usual energy equality between spin-up and spin-down electrons), similarly to ferromagnets.
Researchers at Songshan Lake Materials Laboratory, Southern University of Science and Technology, the Hong Kong University of Science and Technology and other institutes in China recently set out to realize a layered altermagnet that can generate non-collinear spin current. The room-temperature metallic altermagnet they unveiled was outlined in a paper published in Nature Physics.
A team of astronomers at the Space Telescope Science Institute, working with one colleague from the University of St Andrews’ Center for Exoplanet Science and another from the European Southern Observatory, has confirmed the existence of a lone black hole. In their paper published in The Astrophysical Journal, the group describes how they studied newer data regarding an object they had spotted several years ago to confirm its identity.
In 2022, members of essentially the same team reported the discovery of what they described as a “dark object” moving through the constellation Sagittarius. They suggested it might be a lone black hole. Shortly thereafter, a second research team challenged that result, suggesting it was more likely a neutron star. After continuing to study the object, the original research team has found more evidence backing up their original claim that it is likely a lone black hole.
Prior to this new finding, all the black holes that have been identified have also had a companion star —they are discovered due to their impact on light emitted by their companion star. Without such a companion star, it would be very difficult to see a black hole. The one identified by the team was only noticed because it passed in front of a distant non-companion star, magnifying its light and shifting its position in the sky for a short while.
Fifty years since its discovery, scientists have finally worked out how a molecular machine found in mitochondria allows us to make the fuel we need from sugars, a process vital to all life on Earth.
Scientists at the Medical Research Council (MRC) Mitochondrial Biology Unit, University of Cambridge, have worked out the structure of this machine and shown how it operates like the lock on a canal to transport pyruvate—a molecule generated in the body from the breakdown of sugars—into our mitochondria.
Known as the mitochondrial pyruvate carrier, this molecular machine was first proposed to exist in 1971, but it has taken until now for scientists to visualize its structure at the atomic scale using cryo-electron microscopy, a technique used to magnify an image of an object to around 165,000 times its real size. Details are published in Science Advances.
Red roses, the symbol of love, were likely yellow in the past, indicates a large genomic analysis by researchers from Beijing Forestry University, China. Roses of all colors, including white, red, pink, and peach, belong to the genus Rosa, which is a member of the Rosaceae family.
Reconstructing the ancestral traits through genomic analysis revealed that all the roads trace back to a common ancestor —a single-petal flower with yellow color and seven leaflets.
The findings are published in Nature Plants.