The masses of color singlet isotriplet and isosinglet states versus the 4G quark mass from [17] in various formalisms. Curves S1 (iso-singlet ) and T1 (isotriplet ) are the results from covariant gauge formalism. S2 (isosinglet) and T2 (isotriplet) are the results from Salpeter’s equation using only positive frequency components. S3 (isosinglet) and T3 (isotriplet) are the results using both positive and negative frequency components. For more details of these formalisms see [17].
