Swimming robots the size of bacteria can be knocked off course by particles in the fluid they are moving through, but an AI algorithm learns from feedback to get them to their target quickly.
The LHCb Collaboration at CERN has found particles not behaving in the way they should according to the guiding theory of particle physics—the Standard Model.
The Standard Model of particle physics predicts that particles called beauty quarks, which are measured in the LHCb experiment, should decay into either muons or electrons in equal measure. However, the new result suggests that this may not be happening, which could point to the existence of new particles or interactions not explained by the Standard Model.
Physicists from Imperial College London and the Universities of Bristol and Cambridge led the analysis of the data to produce this result, with funding from the Science and Technology Facilities Council. The result was announced today at the Moriond Electroweak Physics conference and published as a preprint.
Scientists at the Large Hadron Collider (LHC) have recorded some highly unusual data that could point to an entirely new force of nature, which would mean a whole new area of physics. The secret lies in an elusive, unstable particle called a B meson, which isn’t biodegrading according to plan.
The scientists at the European Organization for Nuclear Research (CERN) call B mesons “tantalizing tensions,” since the particles break apart into different amounts of electrons and muons than the standard model of physics predicts they should.
B mesons are paired quarks that move together and rapidly decay. While scientists have noticed several previous anomalies in B mesons, this latest observation in decay mode is an even bigger deal. As the B mesons decay in the LHC, there are more electrons and fewer muons than there should be.
Physicists could be on the verge of a major breakthrough as new results hint at a challenge to the standard model of particle physics.
On March 232021 NASA demonstrated Mars Helicopter Ingenuity’s deployment area/place and Perseverance Rover drives directly to Helipad (helicopter deployment site). Ingenuity is nestled up sideways under the belly of the Perseverance rover, with a cover to protect it from the debris kicked up during landing. General thing for successful flight of Mars Helicopter is Space weather. It relates to effects of our Sun’s radiation on Ingenuity. Everything on Mars, including Ingenuity, is bathed in a background of cosmic rays (high energy particles) from our Milky Way galaxy as well as particles from the Sun. When the Sun has a large flare and ejects electrically-charged particles (a so-called coronal mass ejection), the particles travel at high speed toward Mars and Ingenuity, following the Sun’s magnetic lines of force. As our helicopter has a number of elements that are not specifically engineered to be highly robust to these particles, we keep an eye on solar weather events. If such an event is predicted, and is of very large magnitude, we would possibly delay operating Ingenuity for a day or two to let the surge of particles pass by.
Credit: nasa.gov, NASA/JPL-Caltech, NASA/JPL-Caltech/ASU
A hint of the possible existence of a hypothetical particle called a leptoquark has appeared as an unexpected difference in how beauty quarks decay to create electrons or muons. Measured by physicists working on the LHCb experiment on the Large Hadron Collider (LHC) at CERN, the difference appears to violate the principle of “lepton universality”, which is part of the Standard Model of particle physics. The measurement has been made at a statistical significance of 3.1σ, which is well below the 5σ level that is usually considered a discovery. If the violation is confirmed, it could provide physicists with important clues about physics beyond the Standard Model – such as the existence of leptoquarks.
When high-energy protons are smashed together at the LHC large numbers of exotic particles are created, including some containing the beauty quark. These exotic particles quickly decay, and beauty quarks can follow decay paths that involve the production of either electrons or muons, which are both leptons. According to the Standard Model of particle physics, the interactions involved in producing leptons do not discriminate between lepton type, so the rates at which electrons and muons are created by beauty-quark decays are expected to be the same.
Starting in 2014, physicists working on LHCb noticed hints of the violation of this lepton universality. Now, after analysing collision data collected between 2011 and 2018, the researchers have found that the beauty quark appears to favour the electron decay chain over the muon decay chain.
For 50 years, the research community has been hunting unsuccessfully for the so-called Odderon particle. Now, a Swedish-Hungarian research group has discovered the mythical particle with the help of extensive analysis of experimental data from the Large Hadron Collider at CERN in Switzerland.
In 1973, two French particle physicists found that, according to their calculations, there was a previously unknown quasi-particle. The discovery sparked an international hunt.
The Odderon particle is what briefly forms when protons collide in high-energy collisions, and in some cases do not shatter, but bounce off one another and scatter. Protons are made up of quarks and gluons, that briefly form Odderon and Pomeron particles.
In this work, we carry out KS-MD simulations for a range of elements, temperatures, and densities, allowing for a systematic comparison of three RPP models. While multiple RPP models can be selected, 7–11 7. J. Vorberger and D. Gericke, “Effective ion–ion potentials in warm dense matter,” High Energy Density Phys. 9, 178 (2013). https://doi.org/10.1016/j.hedp.2012.12.009 8. Y. Hou, J. Dai, D. Kang, W. Ma, and J. Yuan, “Equations of state and transport properties of mixtures in the warm dense regime,” Phys. Plasmas 22, 022711 (2015). https://doi.org/10.1063/1.4913424 9. K. Wünsch, J. Vorberger, and D. Gericke, “Ion structure in warm dense matter: Benchmarking solutions of hypernetted-chain equations by first-principle simulations,” Phys. Rev. E 79, 010201 (2009). https://doi.org/10.1103/PhysRevE.79.010201 10. L. Stanton and M. Murillo, “Unified description of linear screening in dense plasmas,” Phys. Rev. E 91, 033104 (2015). https://doi.org/10.1103/PhysRevE.91.033104 11. W. Wilson, L. Haggmark, and J. Biersack, “Calculations of nuclear stopping, ranges, and straggling in the low-energy region,” Phys. Rev. B 15, 2458 (1977). https://doi.org/10.1103/PhysRevB.15.2458 we choose to compare the widely used Yukawa potential, which accounts for screening by linearly perturbing around a uniform density in the long-wavelength (Thomas–Fermi) limit, a potential constructed from a neutral pseudo-atom (NPA) approach, 12–15 12. L. Harbour, M. Dharma-wardana, D. D. Klug, and L. J. Lewis, “Pair potentials for warm dense matter and their application to x-ray Thomson scattering in aluminum and beryllium,” Phys. Rev. E 94, 053211 (2016). https://doi.org/10.1103/PhysRevE.94.053211 13. M. Dharma-wardana, “Electron-ion and ion-ion potentials for modeling warm dense matter: Applications to laser-heated or shock-compressed Al and Si,” Phys. Rev. E 86, 036407 (2012). https://doi.org/10.1103/PhysRevE.86.036407 14. F. Perrot and M. Dharma-Wardana, “Equation of state and transport properties of an interacting multispecies plasma: Application to a multiply ionized al plasma,” Phys. Rev. E 52, 5352 (1995). https://doi.org/10.1103/PhysRevE.52.5352 15. L. Harbour, G. Förster, M. Dharma-wardana, and L. J. Lewis, “Ion-ion dynamic structure factor, acoustic modes, and equation of state of two-temperature warm dense aluminum,” Phys. Rev. E 97, 043210 (2018). https://doi.org/10.1103/PhysRevE.97.043210 and the optimal force-matched RPP that is constructed directly from KS-MD simulation data.
Each of the models we chose impacts our physics understanding and has clear computational consequences. For example, success of the Yukawa model reveals the insensitivity to choices in the pseudopotential and screening function and allows for the largest-scale simulations. Large improvements are expected from the NPA model, which makes many fewer assumptions with a modest cost of pre-computing and tabulating forces. (See the Appendix for more details on the NPA model.) The force-matched RPP requires KS-MD data and is therefore the most expensive to produce, but it reveals the limitations of RPPs themselves since they are by definition the optimal RPP.
Using multiple metrics of comparison between RPP-MD and KS-MD including the relative force error, ion–ion equilibrium radial distribution function g (r), Einstein frequency, power spectrum, and the self-diffusion transport coefficient, the accuracy of each RPP model is analyzed. By simulating disparate elements, namely, an alkali metal, multiple transition metals, a halogen, a nonmetal, and a noble gas, we see that force-matched RPPs are valid for simulating dense plasmas at temperatures above fractions of an eV and beyond. We find that for all cases except for low temperature carbon, force-matched RPPs accurately describe the results obtained from KS-MD to within a few percent. By contrast, the Yukawa model appears to systematically fail at describing results from KS-MD at low temperatures for the conditions studied here validating the need for alternate models such as force-matching and NPA approaches at these conditions.
It’s another step on the road to developing quantum information processing applications: A key experiment succeeded in going beyond the previously defined limits for photon applications. Anahita Khodadad Kashi and Prof. Dr. Michael Kues from the Institute of Photonics and the Cluster of Excellence PhoenixD at Leibniz University Hannover (Germany) have demonstrated a novel interference effect. The scientists have thus shown that new color-coded photonic networks can be tapped, and the number of photons involved can be scaled. “This discovery could enable new benchmarks in quantum communication, computational operations of quantum computers as well as quantum measurement techniques and is feasible with existing optical telecommunication infrastructure,” says Kues.
The decisive experiment was successfully performed in the newly established Quantum Photonics Laboratory (QPL) of the Institute of Photonics and the Hannover Centre for Optical Technologies at Leibniz University Hannover. Anahita Khodadad Kashi succeeded in quantum-mechanically interfering independently generated pure photons with different colors, i.e., frequencies. Khodadad Kashi detected a so-called Hong-Ou-Mandel effect.
Hong-Ou-Mandel interference is a fundamental effect of quantum optics that forms the basis for many quantum information processing applications—from quantum computing to quantum metrology. The effect describes how two photons behave when they collide on a spatial beam splitter and explains the phenomenon of quantum mechanical interference.
One of the biggest challenges will be to create superpositions of diamonds that can remain stable over distances of a meter. More than four years ago researchers at Stanford University managed to separate a superposition consisting of 10000 atoms by about half a meter—the current record. “But we’re talking about doing it with diamonds that would have a billion or 10 billion atoms, and that is way more difficult,” Mazumdar says.
Many of the other technologies needed for the device—high vacuums, ultralow temperatures, precisely controlled magnetic fields—have all been achieved separately by various groups. But bringing them together will not be easy. “Just because you can juggle and ride a bike doesn’t mean you can do both at once,” Morley says.
If the device is ever built, it could transform gravitational-wave astronomy. The world’s current gravitational-wave detectors are all firmly anchored to the ground. “The only orientation LIGO can have is due to Earth’s rotation,” Bose says. A small detector such as MIMAC, on the other hand, could be pointed at any direction in the sky. And any physics lab in the world could house it. “The challenge is to get one of them working,” Bose says. “If one of them works, it would be very easy to make several more.”
