STAR experiment are consistent with the existence of the proton–Ω dibaryon. Hypernuclei with higher strangeness Since the Λ is electrically neutral and its nuclear force interactions are attractive, there are predicted to be arbitrarily large hypernuclei with high strangeness and small net charge, including species with no nucleons. Binding energy per baryon in multi-strange hypernuclei can reach up to 21 MeV/A under certain conditions, compared to 8.80 MeV/A for the ordinary nucleus 62Ni. Additionally, formation of Ξ baryons should quickly become energetically favorable, unlike when there are no Λ's, because the exchange of strangeness with a nucleon would be impossible due to the Pauli exclusion principle. Production Several modes of production have been devised to make hypernuclei through bombardment of normal nuclei. Strangeness exchange and production One method of producing a K− meson exchanges a strange quark with a nucleon and changes it to a Λ: p + K− → Λ + π0 n + K− → Λ + π− The cross section for the formation of a hypernucleus is maximized when the momentum of the kaon beam is approximately 500 MeV/c. Several variants of this setup exist, including ones where the incident kaons are either brought to rest before colliding with a nucleus. In rare cases, the incoming K− can instead produce a Ξ hypernucleus via the reaction: p + K− → Ξ− + K+ The equivalent strangeness production reaction involves a π+ meson reacts with a neutron to change it to a Λ: n + π+ → Λ + K+ This reaction has a maximum cross section at a beam momentum of 1.05 GeV/c, and is the most efficient production route for Λ hypernuclei, but requires larger targets than strangeness exchange methods. Elastic scattering Electron scattering off of a proton can change it to a Λ and produce a K+: p + e− → Λ + e− + K+ where the prime symbol denotes a scattered electron. The energy of an electron beam can be more easily tuned than pion or kaon beams, making it easier to measure and calibrate hypernuclear energy levels. Initially theoretically predicted in the 1980s, this method was first used experimentally in the early 2000s. Hyperon capture The capture of a Ξ− baryon by a nucleus can make a Ξ− exotic atom or hypernucleus. Upon capture, it changes to a ΛΛ hypernucleus or two Λ hypernuclei. The disadvantage is that the Ξ− baryon is