Quark mass additivity in hadrons

The authors study mass additivity in hadrons for (i) dynamical quark masses in the chiral limit; (ii) SU(3)- and SU(4)-breaking constituent quark masses; (iii) dynamical plus current mass components in constituent quarks; (iv) current quark masses in Nambu-Goldstone mesons. In all of these case, quark mass additivity appears to be a general phenomenon whose underlying field-theoretic origin is the manifest additivity of boson tadpole insertions at both the strong interaction QCD and weak interaction QFD levels.