What Could Explain the Gallium Anomaly? (quantamagazine.org)
Physicists have ruled out a mundane explanation for the strange findings of an old Soviet experiment, leaving open the possibility that the results point to a new fundamental particle.- Gallium (Wikipedia)
Gallium is a chemical element; it has the symbol Ga and atomic number 31. Discovered by the French chemist Paul-Émile Lecoq de Boisbaudran in 1875, gallium is in group 13 of the periodic table and is similar to the other metals of the group (aluminium, indium, and thallium).