Mirror dark matter: Cosmology, galaxy structure and direct detection

Understand

A simple way to accommodate dark matter is to postulate the existence of a hidden sector.

• That is, a set of new particles and forces interacting with the known particles predominantly via gravity.
• In general this leads to a large set of unknown parameters, however if the hidden sector is an exact copy of the standard model sector, then an enhanced symmetry arises.
• This symmetry, which can be interpreted as space-time parity, connects each ordinary particle ($e, \ \nu, \ p, \ n, \ \gamma, ....)$ with a mirror partner ($e', \ \nu', \ p', \ n', \ \gamma', ...)$.