“The disadvantage is, they’re very unstable and live for a very short amount of time, so we need sensitive methods to produce and detect them, fast.” “Radioactive nuclei could allow us to easily see these symmetry-violating effects,” says study lead author Silviu-Marian Udrescu, a graduate student in MIT’s Department of Physics. Physicists hypothesize that this shape distortion can enhance the violation of symmetries that gave origin to the matter in the universe. But in certain radioactive elements like radium, atomic nuclei are weirdly pear-shaped, with an uneven distribution of neutrons and protons within. Most atoms in nature host a symmetrical, spherical nucleus, with neutrons and protons evenly distributed throughout. Ruiz and his colleagues have published their results today in Physical Review Letters. “That could provide answers to one of the main mysteries of how the universe was created.” “Now we have a chance to measure these symmetry violations, using these heavy radioactive molecules, which have extreme sensitivity to nuclear phenomena that we cannot see in other molecules in nature,” he says. The fact that most of what we see is matter, and there is only about one part per billon of antimatter, means there is a violation of the most fundamental symmetries of physics, in a way that we can’t explain with all that we know,” says Ronald Fernando Garcia Ruiz, assistant professor of physics at MIT. “If the laws of physics are symmetrical as we think they are, then the Big Bang should have created matter and antimatter in the same amount. The fact that they were able to see such small nuclear effects suggests that scientists now have a chance to search such radioactive molecules for even subtler effects, caused by dark matter, for example, or by the effects of new sources of symmetry violations related to some of the current mysteries of the universe. When they measured each molecule’s energy, they were able to detect small, nearly imperceptible changes of the nuclear size, due to the effect of a single neutron. They hand-picked several isotopes of the same molecule, each with one more neutron than the next. The team has developed a new technique to produce and study short-lived radioactive molecules with neutron numbers they can precisely control. And now physicists at MIT and elsewhere have successfully measured a neutron’s tiny effect in a radioactive molecule. Imagine a dust particle in a storm cloud, and you can get an idea of a neutron’s insignificance compared to the magnitude of the molecule it inhabits.īut just as a dust mote might affect a cloud’s track, a neutron can influence the energy of its molecule despite being less than one-millionth its size.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |