bosons = ['W','Z','gamma']
leptons = ['e','mu','tau','nu_e','nu_mu','nu_tau']
mesons = ['pi','K']
baryons = ['N','Omega', 'Delta', 'Lambda', 'Sigma', 'Xi', 'Chi']

neutrals = ['Z', 'gamma', 'pi', 'b', 'rho', 'a', 'eta', 'h', 'omega', 'phi', 'f', 'X', 'chi', 'psi', 'Y']