Standard Model gauge singlet neutrino
= Standard Model gauge singlet neutrino
{c}
A <right-handed neutrino> can transform as $(1,1,0)$ under colour, <weak isospin> and hypercharge. It has no direct Standard Model <gauge coupling>, but may mix with <active neutrinos>. Sterility under the low-energy group does not imply sterility under an enlarged unbroken <gauge group>.