Surprising behavior of hybrid matter: Antimatter atoms in superfluid helium
A hybrid matter—an antimatter helium atom containing an antiproton, the proton's antimatter equivalent in place of an electron, has an unexpected response to laser light when immersed in superfluid helium, reports the ASACUSA collaboration at CERN. The result, described in a paper published today in the journal Nature, may open doors to several lines of research.