Measurement of the cross section for $B_s$ meson production in electron-positron collisions at energies around 11 GeV

Zhukova, Valentina Igorevna (author), Križan, Peter (mentor)

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.

• Language: English
• Keywords: $e^+e^-$ Experiments, Particle and resonance production, B Physics, Quarkonium, Spectroscopy
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: FMF - Faculty of Mathematics and Physics
• Year: 2023
• PID: 20.500.12556/RUL-151720
• COBISS.SI-ID: 169701635
• Publication date in RUL: 18.10.2023

Secondary language

• Language: Slovenian
• Title: Meritev sipalnega preseka za tvorbo mezonov $B_s$ v trkih elektronov in pozitronov v energijskem območju okoli 11 GeV

Abstract

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.

• Keywords: $e^+e^-$ Eksperimenti, Tvorba delcev in resonance, Fizika mezonov B, Kvarkonij, Spektroskopija