Measurement of the e + e − → B s 0 B ¯ s 0 X $$ {B}_s^0{\overline{B}}_s^0X $$ cross section in the energy range from 10.63 to 11.02 GeV using inclusive D s + $$ {D}_s^{+} $$ and D 0 production

Abstract We report the first measurement of the inclusive e + e − → b b ¯ $$ b\overline{b} $$ → D s ± $$ {D}_s^{\pm } $$ X and e + e − → b b ¯ $$ b\overline{b} $$ → D 0 / D ¯ 0 $$ {\overline{D}}^0 $$ 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 B ¯ s 0 $$ {B}_s^0{\overline{B}}_s^0 $$ X) and σ(e + e − → B B ¯ $$ B\overline{B} $$ X) in the same energy range. We measure the fraction of B s 0 $$ {B}_s^0 $$ 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 $$ {B}_s^0 $$ inclusive branching fractions B $$ \mathcal{B} $$ ( B s 0 $$ {B}_s^0 $$ → D 0 / D ¯ 0 $$ {\overline{D}}^0 $$ X)/ B $$ \mathcal{B} $$ ( B s 0 $$ {B}_s^0 $$ → D s ± $$ {D}_s^{\pm } $$ 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.