An experiment that probed particles called gluons, which contain most of the mass of a proton, has revealed that a proton’s radius alters depending on whether you look at the particle’s charge or mass.
By Alex Wilkins
Category: particle physics – Page 268
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New experiments can re-create the young cosmos, when it was a mash of fundamental particles, more precisely than ever before.
Year 2022 😗
Continuous, indefinitely lasting Bose–Einstein condensation, sustained by amplification through Bose-stimulated gain of atoms from a thermal bath, creates a continuous-wave condensate of strontium atoms.
Scientists at Oak Ridge National Laboratory attempted to observe dark matter in a brightly-lit hallway in the basement using the sensitivity of their neutrino detectors. Neutrino Alley, where the team works, is located beneath the Spallation Neutron Source, a powerful particle accelerator. Following up on years of theoretical calculation, the COHERENT team set out to observe dark matter, which is believed to make up to 85% of the mass of the Universe. The experiment allowed the team to extend the worldwide search for dark matter in a new way, and they are planning to receive a much larger and more sensitive detector to improve their chances of catching dark matter particles.
Few things carry the same aura of mystery as dark matter. The name itself radiates secrecy, suggesting something hidden in the shadows of the Universe.
A collaborative team of scientists called COHERENT, including Kate Scholberg, Arts & Sciences Distinguished Professor of Physics, Phillip Barbeau, associate professor of Physics, and postdoctoral scholar Daniel Pershey, attempted to bring dark matter out of the shadows of the Universe and into a slightly less glamorous destination: a brightly lit, narrow hallway in a basement.
Texas A&M University scientists have been working with metal-free, water-based battery electrodes, and they’re finding that the difference in energy storage capacity is as much as 1,000%.
In the scientists’ paper, published in Nature Materials this week, the water-based, or aqueous, batteries consist of a cathode – the negatively charged electrode; an anode – the positively charged electrode; and an electrolyte, like traditional batteries. But in this water-based battery, the cathodes and anodes are polymers that can store energy, and the electrolyte is water mixed with organic salts.
The electrolyte transfers the ions – the charge-carrying particles – back and forth between the cathode and the anode, and the electrolyte is also key to energy storage through its interactions with the electrode.
face_with_colon_three year 2022.
AdS/CFT Proves Its Usefulness
One of the first uses of AdS/CFT had to do with understanding black holes. Theoreticians had long been grappling with a paradox thrown up by these enigmatic cosmic objects. In the 1970s Stephen Hawking showed that black holes emit thermal radiation, in the form of particles, because of quantum mechanical effects near the event horizon. In the absence of infalling matter, this “Hawking” radiation would cause a black hole to eventually evaporate. This idea posed a problem. What happens to the information contained in the matter that formed the black hole? Is the information lost forever? Such a loss would go against the laws of quantum mechanics, which say that information cannot be destroyed.
A key theoretical work that helped tackle this question came in 2006, when Shinsei Ryu and Tadashi Takayanagi used the AdS/CFT duality to establish a connection between two numbers, one in each theory. One pertains to a special type of surface in the volume of spacetime described by AdS. Say there’s a black hole in the AdS theory. It has a surface, called an extremal surface, which is the boundary around the black hole where spacetime makes the transition from weak to strong curvature (this surface may or may not lie inside the black hole’s event horizon). The other number, which pertains to the quantum system being described by the CFT, is called entanglement entropy and is a measure of how much one part of the quantum system is entangled with the rest. The Ryu-Takayanagi result showed that the area of the extremal surface of a black hole in the AdS is related to the entanglement entropy of the quantum system in the CFT.
That means that these two people will say that the state of reality is different – they’d have different facts about where the particle is.
There are may other oddities about quantum mechanics, too. Particles can be entangled in a way that enables them to somehow share information instantaneously even if they’re light years apart, for example. This challenges another common intution: that objects need a physical mediator to interact.
Physicists have therefore long debated how to interpret quantum mechanics. Is it a true and objective description of reality? If so, what happens to all the possible outcomes that we don’t measure? The many worlds interpretation argues they do happen – but in parallel universes.
Nuclear physicists may have finally pinpointed where in the proton a large fraction of its mass resides. A recent experiment carried out at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility has revealed the radius of the proton’s mass that is generated by the strong force as it glues together the proton’s building block quarks. The result was recently published in Nature.
One of the biggest mysteries of the proton is the origin of its mass. It turns out that the proton’s measured mass doesn’t just come from its physical building blocks, its three so-called valence quarks.
“If you add up the Standard Model masses of the quarks in a proton, you only get a small fraction of the proton’s mass,” explained experiment co-spokesperson Sylvester Joosten, an experimental physicist at DOE’s Argonne National Laboratory.
Scientists relied on the holographic principle, which suggests that the two existing theories – particles and gravity – are equivalent.