Study of the leptonic decays of pseudoscalar B,D and vector B*,D* mesons and of the semileptonic B{yields}D and B{yields}D* decays
- Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain)
- Grupo de Fisica Nuclear, Facultad de Ciencias, E-37008 Salamanca (Spain)
We present results for different observables in weak decays of pseudoscalar and vector mesons with a heavy c or b quark. The calculations are done in a nonrelativistic constituent quark model improved at some instances by heavy quark effective theory constraints. We determine pseudoscalar and vector meson decay constants that within a few percent satisfy f{sub V}M{sub V}/f{sub P}M{sub P}=1, a result expected in heavy quark symmetry when the heavy quark masses tend to infinity. We also analyze the semileptonic B{yields}D and B{yields}D* decays for which we evaluate the different form factors. Here we impose heavy quark effective theory constraints among form factors that are not satisfied by a direct quark model calculation. The value of the form factors at zero recoil allows us to determine, by comparison with experimental data, the value of the |V{sub cb}| Cabibbo-Kobayashi-Maskawa matrix element. From the B{yields}D semileptonic decay we get |V{sub cb}|=0.040{+-}0.006, in perfect agreement with our previous determination based on the study of the semileptonic {lambda}{sub b}{yields}{lambda}{sub c} decay and also in excellent agreement with a recent experimental determination by the DELPHI Collaboration. We further make use of the partial conservation of axial current hypothesis to determine the strong coupling constants g{sub B*B{pi}}(0)=60.5{+-}1.1 and g{sub D*D{pi}}(0)=22.1{+-}0.4. The ratio R=(g{sub B*B{pi}}(0)f{sub B*}{radical}(M{sub D}))/(g{sub D*D{pi}}(0)f{sub D*}{radical}(M{sub B}))=1.105{+-}0.005 agrees with the heavy quark symmetry prediction of 1.
- OSTI ID:
- 20709437
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 71, Issue 11; Other Information: DOI: 10.1103/PhysRevD.71.113006; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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