Abstract
The detection of sub-solar mass black holes is a milestone of modern astrophysics as it would open a window either onto new stellar physics or could potentially unveil the nature of Dark Matter as Primordial Black Holes. On November 12, 2025, the LIGO-Virgo-KAGRA (LVK) collaboration reported the compact binary merger candidate S251112cm, a system with no obvious EM counterpart, consistent with binary black hole merger with a chirp mass in the range0.1-0.87 M_(⊙) . The probability that at least one component has mass< 1M_(⊙)is>99% . Inspired by this trigger, we tested if a population of PBHs formed at Quantum Chromodynamics epoch with a broad mass function could account for a signal of this type. Our results, corresponding to a predicted event rate of0.8 \text{yr}{⁻¹}{}as seen by LVK O3b, suggest that the observed merger rate of0.23^(+0.86)_(-0.218) \text{yr}{⁻¹}{ }(95% \text{C.L.}{)}{}if the trigger is confirmed as an astrophysical event would be compatible with such a model. Our predicted detection rate is also in agreement with current LVK expectations for stellar-mass binaries, remaining consistent with a scenario in which a non-negligible fraction of the3-200 M_(⊙)mergers observed by LVK originate from Primordial Black Holes. If confirmed, this detection would place a lower limit to the PBH abundancef_(PBH)>0.04for our adopted model.