First Creation of Anti-Strange Hypernuclei

runagate writes "Brookhaven National Laboratory has created a heretofore unknown form of matter. The matter we normally encounter, and are composed of, has nuclei of protons and neutrons that contain no strange quarks. It was known that anti-strange matter could exist, and using the Solenoidal Tracker at Brookhaven's RHIC, scientists detected a couple of dozen instances of antihypernuclei. The 'Z' axis of the Periodic Table has already been extended in the positive direction by the discovery of hypernuclei, but this new discovery extends it in the negative direction for this new type of 'strange' antimatter — which may exist in the core of collapsed stars and may provide insight into why our universe appears to be made almost solely of matter and not antimatter." The Register's coverage reproduces a helpful diagram.

Comments

Re:so what happens

[Entropius]

No.

Strange quarks behave just like down quarks (which are one of the two constituents of protons and neutrons). The only difference is that they have a higher mass.

Y'know how heavy water is just like light water, except one of the hydrogens is replaced with a deuterium atom? This stuff is similar, except one of the down quarks is swapped with a strange.

Unlike deuterium, though, these lambda baryons are unstable, because the strange quark is unstable. They can decay by the weak interaction (the same thing responsible for beta decay) into an up quark and a couple of leptons (electrons and neutrinos). The amount of time that weak decays take is very long compared to the time-scales involved in quark physics, but it's still very short compared to a second.