Fig. 2.

a Two-dimensional distribution of $m_{{\mathrm{B}}^{+}{\mathrm{K}}^{-}}$ versus $m_{{\mathrm{B}}^{+}{\pi }^{-}}$ in data. b The fitted ${\mathrm{B}}^{+}{\pi }^{-}$ invariant mass distribution. The points represent the data, the thick solid curve is the fit projection, the thin lines indicate the three excited ${\mathrm{B}}^0$ signal contributions, the short-dashed curve is the combinatorial background, and the long-dashed lines show the contributions from the excited ${\mathrm{B}}_{\mathrm{s}}^0$ decays