Measurement of the e+e− → $$ {B}_s^0{\overline{B}}_s^0X $$ cross section in the energy range from 10.63 to 11.02 GeV using inclusive $$ {D}_s^{+} $$ and D0 production
A bstract We report the first measurement of the inclusive e + e − → $$ b\overline{b} $$ bb¯ → $$ {D}_s^{\pm } $$ Ds± X and e + e − → $$ b\overline{b} $$ bb¯ → D 0 / $$ {\overline{D}}^0 $$ D¯0 X cross sections in the energy range from 10 . 63 to 11 . 02 GeV. Based on these results, we determine σ ( e + e − → $$ {B}_s^0{\overline{B}}_s^0 $$ Bs0B¯s0 X ) and σ ( e + e − → $$ B\overline{B} $$ BB¯ X ) in the same energy range. We measure the fraction of $$ {B}_s^0 $$ Bs0 events at Υ(10860) to be f s = ( $$ {22.0}_{-2.1}^{+2.0} $$ 22.0−2.1+2.0 )%. We determine also the ratio of the $$ {B}_s^0 $$ Bs0 inclusive branching fractions $$ \mathcal{B} $$ B ( $$ {B}_s^0 $$ Bs0 → D 0 / $$ {\overline{D}}^0 $$ D¯0 X ) / $$ \mathcal{B} $$ B ( $$ {B}_s^0 $$ Bs0 → $$ {D}_s^{\pm } $$ Ds± X ) = 0 . 416 ± 0 . 018 ± 0 . 092. The results are obtained using the data collected with the Belle detector at the KEKB asymmetric-energy e + e − collider.