nuclear confereneces

Isospin mixing is a concept in nuclear physics that refers to the symmetry in atomic nuclei induced by the nearly identical properties between protons and neutrons. Researchers from the Chinese Academy of Sciences’ Institute of Modern Physics and their collaborators have identified the most significant isospin mixing observed in beta-decay experiments, directly challenging our current understanding of the nuclear force. The findings were featured as an Editors’ Suggestion in the journal Physical Review Letters. In 1932, Werner Heisenberg, a Nobel Prize laureate, introduced the idea of isospin to explain the symmetry in atomic nuclei resulting from the similar properties of protons and neutrons. Isospin symmetry is still widely accepted today. However, isospin symmetry is not strictly conserved due to proton-neutron mass difference, Coulomb interaction, and charge-dependent aspects of nuclear force. Such asymmetry leads to fragmentation of the allowed Fermi transition to many states v...

A major breakthrough has been announced by US scientists in the race to recreate nuclear fusion. Physicists have pursued the technology for decades as it promises a potential source of near-limitless clean energy. On Tuesday researchers confirmed they have overcome a major barrier - producing more energy from a fusion experiment than was put in. But experts say there is still some way to go before fusion powers homes. How does nuclear fusion work? The experiment took place at the National Ignition Facility at the Lawrence Livermore National Laboratory (LLNL) in California. LLNL director Dr Kim Budil said: "This is a historic achievement… over the past 60 years thousands of people have contributed to this endeavour and it took real vision to get us here." Nuclear fusion is described as the "holy grail" of energy production. It is the process that powers the Sun and other stars. It works by taking pairs of light atoms and forcing them together - this "fusion...

Nuclear physicists have discovered a revolutionary way to use the Relativistic Heavy Ion Collider (RHIC) at the U.S. Department of Energy’s Brookhaven National Laboratory to gain insight into the shape and details of atomic nuclei. This method involves using particles of light that surround gold ions as they travel around the collider, as well as a new type of quantum entanglement that has never been observed before. Through a series of quantum fluctuations, the particles of light (a.k.a. photons) interact with gluons—gluelike particles that hold quarks together within the protons and neutrons of nuclei. Those interactions produce an intermediate particle that quickly decays into two differently charged “pions” (p). By measuring the velocity and angles at which these p+ and p– particles strike RHIC’s STAR detector, the scientists can backtrack to get crucial information about the photon—and use that to map out the arrangement of gluons within the nucleus with higher precision than eve...

Atomic nuclei take a range of shapes, from spherical (like a basketball) to deformed (like an American football). Spherical nuclei are often described by the motion of a small fraction of the protons and neutrons, while deformed nuclei tend to rotate as a collective whole. A third kind of motion has been proposed since the 1950s. In this motion, known as nuclear vibration, atomic nuclei fluctuate about an average shape. Scientists recently investigated cadmium-106 using a technique called Coulomb excitation to probe its nuclear shape . They found clear experimental evidence that the vibrational description fails for this isotope's nucleus. This finding is counter to the expected results. Research published in Physics Letters B builds on a long quest to understand the transition between spherical and deformed nuclei . This transition often includes vibrational motion as an intermediate step. The new result suggests that nuclear physicists may need to revise the long-standing para...

Light waves confined in an evaporating water droplet provide a useful model of the quantum behaviour of atoms, researchers in Sweden and Mexico have discovered. Through a simple experiment, a team led by Javier Marmolejo at the University of Gothenburg has shown how the resonance of light inside droplets of specific sizes can provide robust analogies to atomic energy levels and quantum tunnelling When light is scattered by a liquid droplet many times larger than its wavelength, some of the light may reflect around the droplet’s internal edge. If the droplet’s circumference is a perfect multiple of the light’s wavelength inside the liquid, the resulting resonance will cause the droplet to flash brightly. This is an optical example of a whispering gallery mode, whereby sound can reflect around a circular room. This effect was first described mathematically by the German physicist Gustav Mie in 1908 – yet despite the simplicity of the scenario, the rich array of overlapping resonances i...

  International Conference on Nuclear Physics  Scientists using the Relativistic Heavy Ion Collider (RHIC) to study some of the hottest matter ever created in a laboratory have published their first data showing how three distinct variations of particles called upsilons sequentially "melt," or dissociate, in the hot goo. The results, just published in Physical Review Letters, come from RHIC's STAR detector, one of two large particle tracking experiments at this U.S. Department of Energy (DOE) Office of Science user facility for nuclear physics research. The data on upsilons add further evidence that the quarks and gluons that make up the hot matter—which is known as a quark-gluon plasma (QGP)—are "deconfined," or free from their ordinary existence locked inside other particles such as protons and neutrons. The findings will help scientists learn about the properties of the QGP, including its temperature. "By measuring the level of upsilon suppression or di...

International Conference on Nuclear Physics Powerful statistical tools, simulations, and supercomputers explore a billion different nuclear forces and predict properties of the very-heavy lead-208 nucleus. It isn’t easy to describe the structure of a quantum mechanical system of 208 strongly interacting  protons and neutrons based on two and three-nucleon forces. However, powerful statistical tools, machine learning , and models run on supercomputers make it possible to explore a billion different nuclear force models. This allows scientists to make quantitative predictions about the structure of atomic nuclei and their interactions. Scientists used this approach to study the nucleus of lead-208 and predict its neutron skin. This skin is the difference between the radii of the distributions of neutrons versus protons in the nucleus. The result is smaller and more precise than that obtained from a recent experiment. The results show physicists can filter just a few dozen models of ...

As countries across the globe struggle to balance their desire for a reliable energy supply with their contribution to climate change, nuclear power presents a solution. The global reliance on fossil fuels is a function of our energy needs, and although there have been numerous initiatives implemented in order to reduce demand, such as levying large taxes on air transport, appropriate sources of supply still need to be defined. Fossil fuels such as coal, oil and gas have the benefit of being capable of servicing our energy needs. However, they are a chief contributor to climate change, and as countries attempt to meet the Paris Agreement of keeping global temperature below 2o above pre-industrial levels, non-carbon energy sources are essential. Positives and negatives So, what are the pros and cons of nuclear power as a safer, cheaper alternative to fossil fuels? Well, where renewable sources such as wind or solar are clean, they are also intermittent, require an uneven geographical ...

Recent simulations of two black holes colliding at close to the speed of light have shed light on the enigmatic physics behind what has been called by one astrophysicist as “one of the most violent events you can imagine in the universe.” The findings, published in Physical Review Letters, is the first detailed look at the aftermath of such a cataclysmic clash, and shows how a remnant black hole would form and send gravitational waves through the cosmos. Black hole mergers are one of the few events in the universe energetic enough to produce detectable gravitational waves, which carry energy produced by massive cosmic collisions. Like ripples in a pond, these waves flow through the universe distorting space and time. But unlike waves traveling through water, they are extremely tiny, and propagate through “spacetime,” the mind-bending concept that combines the three dimensions of space with the idea of time. This simulation shows two black holes colliding near the speed of light, revea...

Security concerns over radioactive materials have persisted for many years. Airports and other public locations now routinely employ radiation detectors, and nuclear regulators need to be able to monitor the levels of subatomic particles like neutrons. Now, a team of researchers led by the University of Tsukuba has tested a new method of scintillation radiation detection based on wavelength information rather than waveform.In a study published this month in Progress of Theoretical and Experimental Physics, researchers from the Faculty of Pure and Applied Sciences at the University of Tsukuba showed how to detect and distinguish between neutron and gamma-ray sources using data from scintillator emission wavelengths . Often, detectors known as scintillators are used for this purpose. The physical principle of scintillation is similar to the more familiar types of glow-in-the-dark phenomena, such as fluorescence and phosphorescence. In regular fluorescence, a UV photon excites an electron...