Hypercore

A hypernucleus is an atomic nucleus which , in addition to nucleons ( protons and neutrons ), also contains at least one hyperon and thus a strange quark . So hyper nuclei belong to Strange Matter .

Hypernuclei are generated, for example, by the exchange reaction

${\displaystyle K+{\rm {Kern}}\longrightarrow \pi +{\rm {Hyperkern}}}$

being a kaon denoting a pion . ${\displaystyle K}$ ${\displaystyle \pi }$

To designate the hyper kernels, the symbol of the hyperon is given as an index. A ⁵ _Λ He is for example a core consisting of five baryons - two protons and two neutrons, and a Λ particles .

Hypernuclei of light elements that contain the lightest hyperon, the lambda baryon , are  relatively long-lived with lifetimes of around 10 ⁻¹⁰ s, since the lambda can only decay via the weak interaction . It is therefore possible to examine such hypernuclei more closely, in particular to conduct nuclear spectroscopy on them. With some sigma hypernuclei (hypernuclei with sigma baryons , the next heavier hyperons) this has also been successful. Hypernuclei are therefore suitable for studying the behavior of individual particles within atomic nuclei. While with “normal” nuclei one has N  indistinguishable neutrons and Z  indistinguishable protons, with hyper nuclei with the hyperon in the form of this “marked” particle one has a kind of “probe” in the atomic nucleus. This roughly corresponds to the muonic atoms with which one wants to gain knowledge about the atomic shell .

Hypernuclei were discovered in 1952 by the Polish physicists Jerzy Pniewski and Marian Danysz .

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1. ↑ Bogdan Povh et al .: Particles and Cores. 6th edition. Springer-Verlag GmbH, 2004, ISBN 3-540-21065-2 .