Reexamined radiative Decay Bq*→ Bqγ in Light Cone QCD

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The radiative decay Bq*→ Bqγ(q=u,d, or s) is reexamined with a modified light-cone QCD sum rule method, in which adequate chiral operators are chosen as the interpolating fields in the correlators used for a sum rule estimate of the relevant coupling gBq*Bqγ. The resulting sum rules not only show the physical picture consistent with the underlying physics in Bq*→ Bqγ but also avoid the pollution by the nonlocal matrix element < γ(q) | q(x) γμγ₅q(0) | 0>, which starts with twist-3 and thus may bring a large uncertainty to the sum rule predictions. Also, a comparison is made with the previous results from light-cone QCD sum rules and chiral perturbation theory.