ATLAS ran oxygen-on-proton collisions at CERN to mimic cosmic-ray air showers
A 14 September write-up of a Physical Review Letters result describes ATLAS's first lab collisions of oxygen nuclei on protons at CERN, used to mimic cosmic-ray hits in air. Outgoing particles and energies were counted, putting the measured properties more than 10 times sharper than the models had given. Independent same-day news pages for that PRL did not serve.
Science··Night
Oxygen on protons at the LHC
The Conversation describes cosmic-ray nuclei — hydrogen for the most part — hitting nuclei in the air and spawning particle cascades. Those cascade models have been imprecise. ATLAS ran oxygen-on-proton collisions at CERN's Large Hadron Collider and counted outgoing particles and their energies, putting the measured properties more than 10 times sharper than the models had given. The detector is described on the scale of a football pitch, with a silicon camera taking more than 200 million frames a day.[1]
A composition aim, not a finished census
The authors present the collider data as a route to tell hydrogen cosmic rays from heavier nuclei. That composition aim is stated; a finished census of sources is not. The 14 September account is a researcher explanation of the measurement, written for a general reader.[1]
No second newsroom page the same day
The same write-up does not add a second newsroom's independent reconstruction of the dataset. It remains one researcher's account of the first laboratory oxygen-on-proton collisions used to mimic air showers. How large the remaining gap is between those collisions and actual cosmic-ray events is not quantified here.[1]
