December 6, 2018
Theorists prolong a virtually six-decades-old mannequin for the atomic nucleus and use it to foretell form results that the standard mannequin misses.
C. Naya and P. Sutcliffe, Phys. Rev. Lett. (2018)
A well-known however flawed mannequin in nuclear physics is getting a reboot. Launched by Tony Skyrme in 1961, the mannequin describes the nucleus with twists, or “skyrmions,” in a quantum discipline. This description is enticing as a result of it’s certainly one of few that may be related on to quantum chromodynamics, the elemental idea of quarks and gluons. However whereas the skyrmion thought appropriately predicts some nuclear properties, it’s identified to overlook others. Now, Carlos Naya and Paul Sutcliffe of Durham College within the UK have tailored the skyrmion mannequin and proven that, in contrast to the standard model, it appropriately predicts the shapes of a number of mild nuclei.
Skyrme’s unique idea describes the nucleus by way of quark-antiquark pairs referred to as pions. These pions create a quantum discipline, and the variety of twists on this discipline equates to the variety of protons and neutrons (nucleons) within the nucleus. The mannequin appropriately predicts some nuclear properties, similar to sure allowed quantum states. But it surely overestimates nuclear binding energies and fails to foretell the clustering of nucleons that happens in some nuclei.
Naya and Sutcliffe’s extension of the mannequin consists of rho mesons, that are heavier than pions. With this extension, they compute the nucleon density inside nuclei consisting of 1 to eight nucleons. Their new mannequin not solely predicts nucleon clustering results that the unique mannequin misses, but it surely additionally predicts binding energies which can be three instances nearer to the experimental values. The researchers say their revised mannequin doesn’t present a “excellent match” with experiments, but it surely ought to do progressively higher as heavier mesons are integrated.
This analysis is printed in Bodily Evaluation Letters.
Jessica Thomas is the Editor of Physics.
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