1AABOUD 2018AP use ${{\mathit p}}{{\mathit p}}$ collision data at $\sqrt {s }$ = 13 TeV. ${{\mathit X}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ decay is assumed. See their Fig. 9 for limits on $\sigma _{{{\mathit H}{(125)}}}\cdot{}$B( ${{\mathit Z}}{{\mathit X}^{0}}$ ).
2AABOUD 2018AP use ${{\mathit p}}{{\mathit p}}$ collision data at $\sqrt {s }$ = 13 TeV. ${{\mathit X}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ decay is assumed. See their Fig. 10 for limits on $\sigma _{{{\mathit H}{(125)}}}\cdot{}$B( ${{\mathit X}^{0}}{{\mathit X}^{0}}$ ).
References:
AABOUD
2018AP
JHEP 1806 166
Search for Higgs boson decays to beyond-the-Standard-Model light bosons in four-lepton events with the ATLAS detector at $\sqrt{s}=13$ TeV