On the existence of a quadrupole moment in muonium

Abstract

It is shown that even in its ground-state, muonium (hydrogen, mu-nucleonic atom) has a quadrupole moment which is comparable in magnitude nuclear quackupole moments. This leads to a pronounced dfect of inhomogeneous intracrystalline fields on the spin precession and relaxation of p+ mesons and may serve as a basis for carrying out experiments with muonium (mu-nucleonic atoms) which are analogous to quadrupole resonance and relaxation.