An. Ivanov et Ni. Troitskaya, ON HEAVY-TO-HEAVY MESON TRANSITIONS IN THE EFFECTIVE QUARK-MODEL WITHCHIRAL-SYMMETRY, Nuovo cimento della Società Italiana di Fisica. A. Nuclei, particles and fields, 110(1), 1997, pp. 65-115
Heavy-quark effective theory (HQET) and chiral perturbation theory at
the quark level (CHPT)(q), based on the extended Nambu-Jona-Lasinio mo
del with linear realization of chiral U(3) x U(3) symmetry, are applie
d to the calculation of form factors of heavy-to-heavy meson transitio
ns. The application of such an effective quark model has led to the ap
pearance of the additional factor 1/2 distinguishing the normalization
of form factors given within QCD under the admission concerning the u
nrenormalizability of HQET by strong low-energy interactions. One can
explain this factor as a strong influence of heavy-antiquark degrees o
f freedom, which die out in the infinite mass limit in constituent qua
rk loops describing in such an effective quark model strong low-energy
interactions at energies restricted by the spontaneous breaking of ch
iral symmetry scale Lambda(chi) similar or equal to 1 GeV. This should
evidence the renormalization of HQET within such an effective quark m
odel by strong interactions at scales p < Lambda(chi) < M(Q), where M(
Q) is the heavy Q-quark mass. Next-to-leading corrections in chiral an
d heavy-quark mass expansion are computed. The violation of Luke's the
orem within such an effective quark model is observed. The obtained re
sults are confirmed within the effective quark model suggested by Bard
een and Hill.