An innovative method using superconducting sensors precisely measures the recoil energy of lithium-7 nuclei, setting a lower limit on the spatial extent of neutrino wavepackets, advancing understanding of neutrino properties and weak nuclear decays.
Category: particle physics – Page 150
An exception to the laws of thermodynamics: Shape-recovering liquid defies textbooks
A team of researchers led by a physics graduate student at the University of Massachusetts Amherst made the surprising discovery of what they call a “shape-recovering liquid,” which defies some long-held expectations derived from the laws of thermodynamics.
The research, published in Nature Physics, details a mixture of oil, water and magnetized particles that, when shaken, always quickly separates into what looks like the classically curvaceous lines of a Grecian urn.
“Imagine your favorite Italian salad dressing,” says Thomas Russell, Silvio O. Conte Distinguished Professor of Polymer Science and Engineering at UMass Amherst and one of the paper’s senior authors.
Hot Schrödinger cat states created
Quantum states can only be prepared and observed under highly controlled conditions. A research team from Innsbruck, Austria, has now succeeded in creating so-called hot Schrödinger cat states in a superconducting microwave resonator. The study, published in Science Advances, shows that quantum phenomena can also be observed and used in less perfect, warmer conditions.
Schrödinger cat states are a fascinating phenomenon in quantum physics in which a quantum object exists simultaneously in two different states. In Erwin Schrödinger’s thought experiment, it is a cat that is alive and dead at the same time.
In real experiments, such simultaneity has been seen in the locations of atoms and molecules and in the oscillations of electromagnetic resonators.
Iron nitride’s magnetoelastic properties show potential for flexible spintronics
The field of spintronics, which integrates the charge and spin properties of electrons to develop electronic devices with enhanced functionality and energy efficiency, has expanded into new applications.
Beyond current technologies such as hard disk drive read heads and magnetic random-access memory (MRAM), researchers are now investigating flexible spintronics for use in wearable devices and sheet-type sensors.
For these applications, detecting small changes in mechanical stress through electrical resistance modulation is essential. This requires not only materials with significant magnetoresistance effects but also control over their magnetoelastic properties.
New Quark Discovery Reveals a Critical Clue About The Birth of The Universe
A pair of top quarks has been detected in the detritus spraying forth from the collision of two atoms of lead.
It’s the first time that this specific quark-antiquark pair has been spotted in a collision between two nuclei. The detection strengthens evidence that all six quark flavors existed at the dawn of time, in the soupy quark-gluon plasma thought to have suffused the Universe in the moments after the Big Bang.
This means that we’re a step closer to taking new measurements of this primordial soup, and gleaning new insights into how our Universe formed from the very beginning.
Intriguing excess of top-quark pairs hints at discovery of smallest composite particle
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, suggest 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 scrutinized 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.
Proxima Centauri’s Violent Flares May Endanger Life on Nearby Planets
Located just over four light-years away, Proxima Centauri is our closest stellar neighbor and a highly active M dwarf star. While its frequent flaring has long been observed in visible light, a recent study using the Atacama Large Millimeter/submillimeter Array (ALMA) reveals that Proxima Centauri also exhibits intense activity at radio and millimeter wavelengths. These observations provide new insights into the particle-driven nature of its flares and raise important questions about the star’s impact on the habitability of its surrounding planets.
Proxima Centauri is known to host at least one potentially habitable, Earth-sized planet within its habitable zone. Like solar flares on our Sun, Proxima’s flares emit energy across the electromagnetic spectrum and release bursts of high-energy particles known as stellar energetic particles.
The intensity and frequency of these flares could pose a serious threat to nearby planets. If powerful enough, they can erode planetary atmospheres, stripping away critical components like ozone and water, and potentially rendering these worlds uninhabitable.
Scientists discover “Half-Ice, Half-Fire” — A new exotic phase of matter
Discovering and controlling exotic physical states is key in condensed matter physics and materials science. It has the potential to drive advancements in quantum computing and spintronics.
While studying a ferrimagnet model, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory uncovered a new phase of matter called “half-ice, half-fire.” This state is a twin to the “half-fire, half-ice” phase discovered in 2016.
Microwave pulses can control ion-molecule reactions at near absolute zero
A key objective of ongoing research rooted in molecular physics is to understand and precisely control chemical reactions at very low temperatures. At low temperatures, the chemical reactions between charged particles (i.e., ions) and molecules unfold with highly rotational-state-specific rate coefficients, meaning that the speed at which they proceed strongly depends on the rotational states of the involved molecules.
Researchers at ETH Zürich have recently introduced a new approach to control chemical reactions between ions and molecules at low temperatures, employing microwaves (i.e., electromagnetic waves with frequencies ranging from 300 MHz to 300 GHz). Their proposed scheme, outlined in a paper published in Physical Review Letters, entails the use of microwave pulses to manipulate molecular rotational-state populations.
“Over the past 10 years, we have developed a method with which ion-molecule reactions can be studied at very low temperatures, below 10 K, corresponding to the conditions in giant molecular clouds in the interstellar medium, where these types of reactions play a key role,” Valentina Zhelyazkova, corresponding author of the paper, told Phys.org.
Repurposed smartphone camera sensors create real-time, high-resolution imaging of antiproton annihilations
Did you know that the camera sensor in your smartphone could help unlock the secrets of antimatter? The AEgIS collaboration, led by Professor Christoph Hugenschmidt’s team from the research neutron source FRM II at the Technical University of Munich (TUM), has developed a detector using modified mobile camera sensors to image, in real time, the points where antimatter annihilates with matter.
This new device, described in a paper published in Science Advances, can pinpoint antiproton annihilations with a resolution of about 0.6 micrometers, a 35-fold improvement over previous real-time methods.
AEgIS and other experiments at CERN’s Antimatter Factory, such as ALPHA and GBAR, are on a mission to measure the free-fall of antihydrogen within Earth’s gravitational field with high precision, each using a different technique. AEgIS’s approach involves producing a horizontal beam of antihydrogen and measuring its vertical displacement using a device called a moiré deflectometer that reveals tiny deviations in motion and a detector that records the antihydrogen annihilation points.