Revisiting rescattering contributions to $$ \overline{B} $$(s) → $$ {D}_{(s)}^{\left(\ast \right)}M $$ decays

Abstract

Motivated by the reported discrepancies between experimental data and Standard Model predictions for the branching ratios of the color-allowed decays $$ \overline{B} $$ B ¯ 0 → D(*)+K− and $$ {\overline{B}}_s^0 $$ B ¯ s 0 → $$ {D}_s^{\left(\ast \right)+}{\pi}^{-} $$ D s ∗ + π − , we study final-state rescattering effects on $$ \overline{B} $$ B ¯ (s) → $$ {D}_{(s)}^{\left(\ast \right)}P $$ D s ∗ P and $$ \overline{B} $$ B ¯ (s) → D(s)V, where P(V) is a light pseudoscalar (vector) meson. We consider quasi-elastic rescatterings in the framework of SU(3) and U(3) flavor symmetries, and find that the effects cannot explain the measured branching ratios of the color-allowed and color-suppressed decays simultaneously. We also perform global fits to the $$ \overline{B} $$ B ¯ (s) → $$ {D}_{(s)}^{\left(\ast \right)}P $$ D s ∗ P and $$ \overline{B} $$ B ¯ (s) → D(s)V data, allowing for new physics contributions to the Wilson coefficient a1 associated with the color-allowed tree amplitudes. It is shown that the fits prefer a downward shift of $$ \mathcal{O} $$ O (10%) in a1 even in the presence of the quasi-elastic rescattering contributions.

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