Discovering Partonic Rescattering in Light Nucleus Collisions

We demonstrate that oxygen-oxygen 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 oxygen-oxygen 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 GeV < p(T) < 100 GeV.

Automated summary

In this study, oxygen-oxygen collisions at the LHC were used to investigate parton energy loss and it was found that measuring charged hadron spectra can distinguish the expected signal from the baseline.