Measurement of the cross section for $B_s$ meson production in electron-positron collisions at energies around 11 GeVZhukova, Valentina Igorevna (Avtor) Križan, Peter (Mentor) $e^+e^-$ ExperimentsParticle and resonance productionB PhysicsQuarkoniumSpectroscopyWe report the first measurement of the inclusive $\sigma(e^+e^-\to b\bar{b}\to D_s^+X)$ and $\sigma(e^+e^-\to b\bar{b}\to D^0/\bar{D}^0X)$ cross sections in the energy range from 10.63 to 11.02 GeV. Based on these results we determine $\sigma(e^+e^-\to B_s^0\bar{B}_s^0 X)$ and $\sigma(e^+e^-\to B\bar{B}X)$ cross sections in the same energy range. We measure the fraction of $B_s^0$ events at $\Upsilon(10860)$ to be $f_{\rm s}=(22.0^{+2.0}_{-2.1})\%$. We determine also the ratio of the $B_s^0$ inclusive branching fractions $\mathcal{B}(B_s^0 \to D^0X)/\mathcal{B}(B_s^0 \to D_s^+ X)=0.416 \pm 0.018 \pm 0.092$. The results are obtained using the data collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider.20232023-10-18 08:15:08Doktorsko delo/naloga151720sl