Measurement of $Ω^0_{\rm c}$ baryon production and branching-fraction ratio ${\rm BR(Ω^0_c \rightarrow Ω^- e^+ν_e)} / {\rm BR(Ω^0_c \rightarrow Ω^- π^+)}$ in pp collisions at $\sqrt{s}$ = 13 TeV

The inclusive production of the charm-strange baryon $\Omega^{0}_{\rm c}$ is measured for the first time via its semileptonic decay into $\Omega^{-}\rm e^{+}\nu_{e}$ at midrapidity ($|y|<~0.8$) in proton$-$proton (pp) collisions at the centre-of-mass energy $\sqrt{s}=13$ TeV with the ALICE detector at the LHC. The transverse momentum ($p_{\rm T}$) differential cross section multiplied by the branching ratio is presented in the interval $2<~p_{\rm T}<~12~{\rm GeV}/c$. The branching-fraction ratio ${\rm BR}(\Omega^0_{\rm c} \rightarrow \Omega^{-}{\rm e}^{+}\nu_{\rm e})/ {\rm BR}(\Omega^0_{\rm c} \rightarrow \Omega^{-}{\pi}^{+})$ is measured to be 1.12 $\pm$ 0.22 (stat.) $\pm$ 0.27 (syst.). Comparisons with other experimental measurements, as well as with theoretical calculations, are presented.

 

Phys. Rev. D 110, 032014 (2024)
HEP Data
e-Print: arXiv:2404.17272 | PDF | inSPIRE
CERN-EP-2024-112
Figure group

Figure 1

Left panel: invariant-mass distribution of opposite-sign pairs (black solid circle marker) and same-sign pairs (red solid square marker) in SE, and opposite-sign pairs (blue open square marker) in ME. Right panel: invariant-mass distribution of the $\Omega^0_{\rm c}$ candidates obtained by subtracting the opposite-sign charge e$\Omega$ pairs in ME from the opposite-sign charge pairs in SE (black solid circle marker), and e$\Omega$ opposite-sign charge pairs coming from $\Omega^0_{\rm c}$ decay from PYTHIA 8 (green open circle marker).

Figure 2

Left panel: correlation matrix between the generated $\Omega^0_{\rm c}$ baryon $p_{\rm T}$ and the reconstructed opposite-sign charge pairs, obtained from the simulation based on PYTHIA 8 described in Ref. [15]. Right panel: product of $({\rm A}\times\varepsilon)$ for inclusive $\Omega^0_{\rm c}$ baryons in pp collisions at $\sqrt{s} =$ 13 TeV as a function of $p_{\rm T}$.

Figure 3

Top panel: $p_{\rm T}$-differential production cross sections of inclusive $\Omega^0_{\rm c}$ baryons multiplied by the branching ratios (BR) into $\Omega^{-}{\rm e}^{+}\nu_{\rm e}$ and $\Omega^{-}\pi^{+}$ in pp collisions at $\sqrt{s}$ = 13 TeV. Bottom panel: $p_{\rm T}$-differential branching-fraction ratio ${\rm BR}(\Omega^0_{\rm c} \rightarrow \Omega^{-}{\rm e}^{+}\nu_{\rm e})/ {\rm BR}(\Omega^0_{\rm c} \rightarrow \Omega^{-}{\pi}^{+})$.

Figure 4

Comparison of ${\rm BR}(\Omega^0_{\rm c} \rightarrow \Omega^{-}{\rm e}^{+}\nu_{\rm e})/ {\rm BR}(\Omega^0_{\rm c} \rightarrow \Omega^{-}{\pi}^{+})$ between experiments and theoretical calculations .