Hyperonnucleon

Hyperonnucleon is a proposed dibaryon consisting of a hyperon bound to a nucleon by the strong interaction. As a two-baryon system, it would carry baryon number 2 and nonzero strangeness: for example, a Lambda-N or Sigma-N pair has strangeness S = −1, while a Xi-N pair has S = −2. The concept arises in studies of hyperon-nucleon interactions and the possible formation of bound states beyond ordinary nuclei.

The idea rests on models of baryon-baryon forces, including meson-exchange frameworks, effective field theories, and insights from lattice quantum chromodynamics. Binding depends on the specific channel (which hyperon is involved and whether the partner is a proton or neutron) and on the strength and range of the interaction. SU(3) flavor symmetry provides a organizing principle, but empirical constraints are limited by the scarcity of hyperon-nucleon scattering data. Predictions range from weakly bound states to resonant or unbound systems, and lattice calculations continue to refine the viability of such states.

Experimentally, there is no unambiguous observation of a stable hyperonnucleon bound state. Searches in hypernuclear physics and heavy-ion experiments have explored dibaryon candidates with strangeness, but definitive evidence remains elusive. The lack of a confirmed state imposes constraints on YN interaction models, while ongoing experiments and improved lattice results aim to clarify whether a hyperonnucleon dibaryon could exist and under what conditions.

If present, hyperonnucleons would influence our understanding of hyperon-nucleon forces and could have implications for the equation of state of dense matter in neutron stars and other astrophysical environments. See also hypernucleus, dibaryon, H-dibaryon, hyperon, nucleon.