Dibaryons – a new state of matter?

Abstract

New results in the field of dibaryons are discussed concentrating on the d∗(2380) resonance with I(JP) = 0(3+), which has been observed first in the double-pionic fusion to deuterium and meanwhile also in neutron-proton scattering — establishing it thus as a genuine s-channel resonance. Double-pionic fusion reactions to the He isotopes demonstrate that this resonance survives also in a nuclear surrounding. It also has been shown to contribute to dilepton production helping thus to resolve the so-called DLS puzzle. Moreover, the existence of dibaryons has also an impact on the equation of state for nuclear matter