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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 ve...

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Detalles Bibliográficos
Autor principal: David, André
Lenguaje:eng
Publicado: 2006
Materias:
Acceso en línea:https://dx.doi.org/10.1016/j.physletb.2006.10.071
http://cds.cern.ch/record/1047414
Descripción
Sumario: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.