Speaker
Dr
Hiroyuki Fujioka
(Kyoto University)
Description
A pseudoscalar meson may be bound in a nucleus, if the interaction between the meson and the nucleon is attractive enough. In particular, the possible existence of kaonic nuclei attracts both experimentalists and theorists in these days. Two experimental groups, FINUDA and DISTO, claim the observation of K-pp bound states in different reactions, although hot debate with regard to the existence of deeply-bound K-pp states is still going on.
Two experiments with secondary meson beam will be carried out in near future at J-PARC. The E15 experiment will utilize the (K-, n) reaction on liquid 3He target, whereas the J-PARC E27 experiment will investigate the (pi+, K+) reaction on liquid deuterium target. A characteristic decay mode of K-pp into Lambda+p will be tagged in both the experiments so as to reduce irrelevant backgrounds.
By the way, it is also known that an eta meson and a nucleon is weakly attractive. The eta-nucleus interaction has been investigated by use of near-threshold eta production. An alternative way to assess the strength of the interaction is to measure the binding energy and the decay width of eta-mesic nuclei, if they do exist. Such an experiment may be possible with pion beam at J-PARC, as well as MAMI (photon beam) and COSY (proton/deuteron beam).
In this contribution, the author will introduce experimental programs at J-PARC, focusing on kaonic nuclei and eta-mesic nuclei.
Primary author
Dr
Hiroyuki Fujioka
(Kyoto University)