Inspired by recent observations of $T_{ c\bar{ s}0}(2900)^0$ in the $D_s^+ \pi^-$ invariant mass distribution of $B^0 \to \bar{ D}^0 D_s^+ \pi^-$ decay and $T_{ c\bar{ s}0}(2900)^{ ++}$ in the $D_s^+ \pi^+$ invariant mass distribution of $B^+ \to D^- D_s^+ \pi^+$ decay, we investigate the $T_{ c\bar{ s}0}(2900)^{ ++}$ contribution to the $B^+ \to K^+ D^+ D^-$ decay in a molecular scenario, where we consider $T_{ c\bar{ s}0}(2900)r^{ ++}$ as a $D^{ \ast +} K^{ \ast+}$ molecular state. Our estimations indicate that the fit fraction of $T_{ c\bar{ s}0}(2900)^{ ++}$ in the $B^+ \to K^+ D^+ D^-$ is about $12.5\%$, and its signal is visible in the $D^+ K^+$ invariant mass distribution. With the involvement of $T_{ c\bar{ s}0}(2900)^{ ++}$, the fit fractions of $\chi_{ c0}(3915)$ and $\chi_{ c2}(3930)$ may be much different with the ones obtained by the present amplitude analysis [Phys. Rev. D \textbf{ 102}, 112003 (2020)], which may shed light on the long standing puzzle of $\chi_{ c0}(3915)$ as the conventional charmonium.
Categories: hep-ph hep-ex