From Barry Adams
Stuart Clark may be looking for dark matter under the wrong name (7 January, p 30). The idea that the universe contains a complete but invisible copy of ordinary matter dates back to 1957, when Chien-Shiung Wu discovered that the weak nuclear force, one of four fundamental natural forces, only interacts with left-handed particles.
Since then, Wu and her team and a few others have investigated the possible existence of a reflected copy of ordinary matter where only right-handed particles interact with a right-handed weak force, so-called “mirror matter”.
Mirror matter seems not only to be viable as a dark matter candidate, but a better match for observations at the CRESST, CoGeNT and DAMA experiments.
London, UK
