  We demonstrate that oxygen-oxygen (OO) collisions at the LHC provide
unprecedented sensitivity to parton energy loss in a system whose size is
comparable to those created in very peripheral heavy-ion collisions. With
leading and next-to-leading order calculations of nuclear modification factors,
we show that the baseline in the absence of partonic rescattering is known with
up to 2% theoretical accuracy in inclusive OO collisions. Surprisingly, a
$Z$-boson normalized nuclear modification factor does not lead to higher
theoretical accuracy within current uncertainties of nuclear parton
distribution functions. We study a broad range of parton energy loss models and
we find that the expected signal of partonic rescattering can be disentangled
from the baseline by measuring charged hadron spectra in the range
$20\,\text{GeV}<p_T<100\,\text{GeV}$
