ProHyPro · Production and decay of Hypernuclei by using an intense heavy-ion beam incidenting on a Proton target

Production and decay of Hypernuclei by using an intense heavy-ion beam incidenting on a Proton target

Hyperons are expected to be an important building block of high-density matter such as neutron stars. However, the hyperon-nucleon (YN) and hyperon-hyperon (YY) interactions are rarely known because the short lifetime of hyperons (hundreds of ps) making it extremely difficult to perform scattering or capture experiments with hyperon beams. Hypernuclei, which contains at least one hyperon in addition to the normal protons and neutrons, provide an alternative and unique ground to study the YN and YY interactions. The study of hypernuclei sheds new light on the world of traditional nuclei by revealing new symmetries and new phenomena produced by the additional strangeness dimension. Hyperons, at variance with nucleons, are free from Pauli blocking and play a glue-like role if embodied in a nucleus. The measured binding energies and energy gap between the spin doublet give precise information on the YN in medium interaction. Study of YY interaction is expected by measuring the fine structure of double-hypernuclei. Furthermore, the first excited state of the lambda particle is 70 MeV, much less than the lowest excitation of the nucleons around 300 MeV, leading to stronger three-body force effects. In astrophysics, the presence of hyperons could either soften or stiffen the equation of state (EOS) of high-density nuclear matter depending on the detailed properties of the YY interaction and the YNN three-body interaction. In the past decades, (K-, pi-), (pi+, K+) and (e, e’K+) reactions has been widely used to produce hypernuclei in the laboratories. In these reactions, stable targets are used, and therefore most of the studied hypernuclei are limited to on/near the beta-stability line. New techniques aiming to produce exotic hypernuclei (neutron-rich or proton-rich) are ongoing which is important to obtain knowledge of the YNN three-body interaction and the density dependence of the YN interaction. This project (ProHyPro) aims at investigating the production and decay of hypernuclei by using an intense heavy-ion beam interacting with a proton target.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз