麻豆淫院

An international team of physicists has successfully measured the size of a certain type of neutrino to a certain degree. In their paper in the journal Nature, the group describes experiments they conducted that involved measuring the radioactive decay of the element beryllium.

Neutrinos are subatomic particles with a mass very close to zero. They also have a half-integer spin and rarely react with normal matter. To date, three kinds of neutrinos have been identified, each by association with an electron, muon or tau particle. 麻豆淫院icists have become more interested in neutrinos over the past several years because it is thought better understanding them may lead to a better understanding of why there is more matter than antimatter in the known universe.

One of the first questions that needs to be answered about neutrinos is their size. This is important for designing appropriately sized and shaped neutrino detectors. Currently, these detectors are very large to increase the likelihood of capturing neutrinos, which interact very weakly with matter. In this new effort, the research team conducted experiments involving the radioactive decay of beryllium to measure the spatial extent of an electron-associated neutrino's wave packet.

The experiment consisted of measuring radioactive decay in beryllium, which decayed into lithium. As it does so, an electron in a single atom combines with a proton, producing a neutron, resulting in the creation of a lithium atom. As that happens, energy is released, pushing the atom in one direction and the neutrino produced in the other. By starting the process in a particle accelerator and placing extremely sensitive neutrino detectors along the sides, they were able to measure the momentum of the lithium atoms and use that to calculate the size of the neutrino.

The experiments established a lower limit on the spatial extent of the neutrino's wave packet at 6.2 picometers. This measurement reflects the quantum mechanical nature of neutrinos, where the 'size' pertains to the spatial uncertainty of their wave packet, rather than a physical dimension. The findings suggest that the neutrino's wave packet is localized at a scale significantly larger than a typical atomic nucleus, offering new insights into the quantum properties of neutrinos.

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