Invariant-mass spectra of $^{4}_{\overline{\Lambda}}\overline{\rm He}$ candidates on the left and $^{4}_{\overline{\Lambda}}\overline{\rm H}$ candidates on the right. These spectra are fitted with a KDE template for the signal peak (blue curve) and an exponential function to model the background (orange curve). The combined invariant-mass spectra for the sum of particle and antiparticle states of each (anti)hypernucleus are shown in the End Matter.