Lifeboat Foundation

In particle physics, particles are constantly interacting and interfering with all the other kinds of particles, but the strength of those interactions depend on the particle masses. So, when we try to evaluate anything involving the Higgs boson – like, say, its ability to maintain the separation between the electromagnetic and weak nuclear forces – we also need to pay attention to how the other particles will interfere with that effort. And since the top quark is handily the biggest of the bunch (the next largest, the bottom quark, weighs a mere 5 GeV) it’s essentially the only other particle we need to care about.

When physicists first calculated the stability of the universe, as determined by the Higgs boson’s ability to maintain the separation of the electroweak force, they didn’t know the mass of either the Higgs itself or the top quark. Now we do: The top quark weighs around 175 GeV, and the Higgs around 125 GeV.

Plugging those two numbers into the stability equations reveals that the universe is… metastable. This is different than stable, which would mean that there’s no chance of the universe splitting apart instantly, but also different than unstable, which would mean it already happened.

Future of in space manufacturing, next 10 years of cisLunar, getting kids involved in stem, and more with Joe Pawelski Architect of CisLunar.

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They have found no signs of the event yet.

Deep in Italy’s Gran Sasso mountains, in the National Institute for Nuclear Physics’ (INFN) underground laboratories, researchers have been searching for proof of a very small violation of a fundamental quantum tenet called the Pauli exclusion principle, according to an article by Phys.org published on Monday.

The principle, that is applied to everything, dictates that electrons can only arrange themselves in certain specific ways in atoms. These arrangements make it so we are made of solid matter.

We see the world around us because light is being absorbed by specialized cells in our retina. But can vision happen without any absorption at all—without even a single particle of light? Surprisingly, the answer is yes.

Imagine that you have a camera cartridge that might contain a roll of photographic film. The roll is so sensitive that coming into contact with even a single photon would destroy it. With our everyday classical means there is no way there’s no way to know whether there’s film in the cartridge, but in the quantum world it can be done. Anton Zeilinger, one of the winners of the 2022 Nobel Prize in Physics, was the first to experimentally implement the idea of an interaction-free experiment using optics.

Now, in a study exploring the connection between the quantum and classical worlds, Shruti Dogra, John J. McCord, and Gheorghe Sorin Paraoanu of Aalto University have discovered a new and much more effective way to carry out interaction-free experiments. The team used transmon devices—superconducting circuits that are relatively large but still show quantum behavior—to detect the presence of microwave pulses generated by classical instruments. Their research was recently published in Nature Communications.

Today the international LHCb collaboration at the Large Hadron Collider (LHC) presented new measurements of rare particle transformations, or decays, that provide one of the highest-precision tests yet of a key property of the Standard Model of particle physics, known as lepton flavor universality.

Previous studies of these decays had hinted at intriguing tensions with the theoretical predictions, potentially due to the effects of new particles or forces. The results of the improved and wider-reaching analysis based on the full LHC dataset collected by the experiment during Run 1 and Run 2, which were presented at a seminar at CERN held this morning, are in line with the Standard Model expectation.

A central mystery of particle physics is why the 12 elementary quarks and leptons are arranged in pairs across three generations that are identical in all but mass, with ordinary matter comprising particles from the first, lightest generation. Lepton flavor universality states that the fundamental forces are blind to the generation to which a lepton belongs.

The first measurements from a newly built gamma-ray observatory have been analyzed for signs of the decay of heavy dark matter, putting a lower limit on the hypothetical particles’ lifetime.

A pressing quest in the field of nanoelectronics is the search for a material that could replace silicon. Graphene has seemed promising for decades. But its potential has faltered along the way, due to damaging processing methods and the lack of a new electronics paradigm to embrace it. With silicon nearly maxed out in its ability to accommodate faster computing, the next big nanoelectronics platform is needed now more than ever.

Walter de Heer, Regents’ Professor in the School of Physics at the Georgia Institute of Technology, has taken a critical step forward in making the case for a successor to silicon. De Heer and his collaborators have developed a new nanoelectronics platform based on graphene —a single sheet of carbon atoms. The technology is compatible with conventional microelectronics manufacturing, a necessity for any viable alternative to silicon.

In the course of their research, published in Nature Communications, the team may have also discovered a new quasiparticle. Their discovery could lead to manufacturing smaller, faster, more efficient and more sustainable computer chips, and has potential implications for quantum and high-performance computing.

“My first impression is that the analysis is much more robust than before,” says Florencia Canelli, an experimental particle physicist at the University of Zurich in Switzerland who is a senior member of a separate LHC experiment. It has revealed how a number of surprising subtleties had conspired to produce an apparent anomaly, she says.

Renato Quagliani, an LHCb physicist at the Swiss Federal Polytechnic Institute (EPFL) in Lausanne, reported the results at CERN on 20 December, in a seminar that also attracted more than 700 viewers online. The LHCb collaboration also posted two preprints on the arXiv repository^1,2.

LHCb first reported a tenuous discrepancy in the production of muons and electrons in 2014. When collisions of protons produced massive particles called B mesons, these quickly decayed. The most frequent decay pattern produced another type of meson, called a kaon, plus pairs of particles and their antiparticles — either an electron and a positron or a muon and an antimuon. The standard model predicted that the two types of pairs should occur with roughly the same frequency, but LHCb data suggested that the electron-positron pairs occurred more often.

For decades, physicists have been hunting for a quantum-gravity model that would unify quantum physics, the laws that govern the very small, and gravity. One major obstacle has been the difficulty in testing the predictions of candidate models experimentally. But some of the models predict an effect that can be probed in the lab: a very small violation of a fundamental quantum tenet called the Pauli exclusion principle, which determines, for instance, how electrons are arranged in atoms.

A project carried out at the INFN underground laboratories under the Gran Sasso mountains in Italy, has been searching for signs of radiation produced by such a violation in the form of atomic transitions forbidden by the Pauli exclusion principle.

In two papers appearing in the journals Physical Review Letters (published on September 19, 2022) and Physical Review D (accepted for publication on December 7, 2022) the team reports that no evidence of violation has been found, thus far, ruling out some quantum-gravity models.