Is the fragmentation of charm quarks into D mesons described by heavy quark effective theory?

Heavy quark effective theory predicts that produced charm quarks have the same probability to fragment into any of the four D mesons with orbital angular momentum L=0: the singlet D state and the triplet D∗ states. This would imply PV(D∗,D)=3/4, where PV is the ratio between directly produced L=0 vector states (D∗) and all L=0 (D and D∗) states. Experimental data collected in several different collision systems (e+e−, hadro-production, photo-production, etc.) and over a broad range of collision energies, show that PV(D∗,D)=0.594±0.010. From this observation, it follows that “naive spin counting” does not apply to charm production, implying a revision of charm production calculations where this assumption is made.