20.500.12556/RUL-151720 Measurement of the cross section for $B_s$ meson production in electron-positron collisions at energies around 11 GeV Meritev sipalnega preseka za tvorbo mezonov $B_s$ v trkih elektronov in pozitronov v energijskem območju okoli 11 GeV We 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. Poročamo o prvi meritvi inkluzivnih presekov $\sigma(e^+e^-\to b\bar{b}\to D_s^+X)$ in $\sigma(e^+e^-\to b\bar{b}\to D^0/\bar{D}^0X)$ v energijskem območju od 10.63 do 11.02 GeV. Na podlagi teh rezultatov določimo v istem energijskem območju preseke $\sigma(e^+e^-\to B_s^0\bar{B}_s^0 X)$ in $\sigma(e^+e^-\to B\bar{B}X)$. Izmerimo tudi delež dogodkov $B_s^0$ pri resonanci $\Upsilon(10860)$, $f_{\rm s}=(22.0^{+2.0}_{-2.1})\%$, in razmerje $B_s^0$ inkluzivnih razvejitvenih razmerij $\mathcal{B}(B_s^0 \to D^0X)/\mathcal{B}(B_s^0 \to D_s^+ X)=0.416 \pm 0.018 \pm 0.092$. Rezultati so pridobljeni s pomočjo podatkov, zbranih z detektorjem Belle na asimetričnem $e^+e^-$ trkalniku KEKB. $e^+e^-$ Experiments Particle and resonance production B Physics Quarkonium Spectroscopy $e^+e^-$ Eksperimenti Tvorba delcev in resonance Fizika mezonov B Kvarkonij Spektroskopija true false false Angleški jezik Slovenski jezik Doktorsko delo/naloga 2023-10-18 08:15:08 2023-10-18 08:15:10 2023-10-24 14:27:53 0000-00-00 00:00:00 2023 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 138391 169701635 11942.pdf 11942.pdf 1 90EAAD5BBD695C2FD064BF885D7C8905 efb55a50472f2c11375aff9a34ddc32a2f2badea7702c317c721f2697b2d1e20 b1c50849-6d7d-11ee-8bea-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=176764 Fakulteta za matematiko in fiziko 0 0 0