The plot in the answer of Luc J. Bourhis shows that the disagreement is a matter of context.I am referring to that plot in this complimentary answer.

Your question

"resonant behaviour"?

Resonant behavior in scattering particles,e+e- in this case, indicates a particle with the invariant mass of the two input particles, in this case a Ψ, but different quantum numbers in the decay products .

Looking at the plot provided:

At the Ψ resonance the existence of new quarks was established, and the need of 3 GeV energy is supported .

The creation of charm quantum numbers in separate charmed hadrons in order to see the charges contributing needs more energy . The creation of D mesons almost with a mass close to 2 GeV, in the plot, become evident in the ratio at around 4 GeV .

At 3GeV, one is close to twice the c quark mass so would not expect asymptotic freedom to hold so the above formula does not apply, and in fact would expect to see resonant behaviour.

Asymptotic freedom is the assumption of QCD that at very high energies the quarks will be free , and the paragraph uses it for distinguishing between constituent mass and current mass. Current mass is the mass that quarks have in QCD calculations and the one shown in the standard model . Quarks are "dressed" with virtual particles within hadrons and the charge argument cannot be used. They are handwaving the argument that at the resonance of Ψ it is a bad approximation to assume that the e+e- generate just the current quarks, the extra quarks will dress the charmed quark into its constituent mass . They assume that current quarks are involved when there are no hadronic resonances to mask the charges. They equate the use of the current quarks masses to asymptotic freedom.

(in calculations with Feynman diagrams always the current masses are used)

In summary:

If one assumes the Ψ peak as a clear indication of new quarks needed to interpret it, one goes to 3 GeV . If one wants to measure the charge and color content the plot shows that one needs 4 GeV and more

The plot in the answer of Luc J. Bourhis shows that the disagreement is a matter of context.I am referring to that plot in this complimentary answer.

Your question

"resonant behaviour"?

Resonant behavior in scattering particles,e+e- in this case, indicates a particle with the invariant mass of the two input particles, in this case a Ψ, but different quantum numbers in the decay products .

Looking at the plot provided:

At the Ψ resonance the existence of new quarks was established, and the need of 3 GeV energy is supported .

The creation of charm quantum numbers in separate charmed hadrons in order to see the charges contributing needs more energy . The creation of D mesons almost with a mass close to 2 GeV, in the plot, become evident in the ratio at around 4 GeV .

At 3GeV, one is close to twice the c quark mass so would not expect asymptotic freedom to hold so the above formula does not apply, and in fact would expect to see resonant behaviour.

Asymptotic freedom is the assumption of QCD that at very high energies the quarks will be free , and the paragraph uses it for distinguishing between constituent mass and current mass. Current mass is the mass that quarks have in QCD calculations and the one shown in the standard model . Quarks are "dressed" with virtual particles within hadrons and the charge argument cannot be used. They are handwaving the argument that at the resonance of Ψ it is a bad approximation to assume that the e+e- generate just the current quarks, the extra quarks-antiquarks-gluons in a hadron will dress the charmed quark into its constituent mass . They assume that current quarks are involved when there are no hadronic resonances to mask the charges. They equate the use of the current quarks masses to asymptotic freedom.

(in calculations with Feynman diagrams always the current masses are used)

In summary:

If one assumes the Ψ peak as a clear indication of new quarks needed to interpret it, one goes to 3 GeV . If one wants to measure the charge and color content the plot shows that one needs 4 GeV and more