polystyrene worked

I would not have guessed this would work - a novel technique for probing the proton's structure with neutrinos.

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To measure the proton structure with high precision, scientists ideally would send neutrinos or antineutrinos into a very dense target made only of hydrogen, which contains protons but no neutrons. That is experimentally challenging, if not impossible to achieve. Instead, the MINERvA detector contains hydrogen that is closely bonded to carbon in the form of a plastic called polystyrene. But no one had ever tried to separate hydrogen data from carbon data.

“If we were not optimists, we would say it’s impossible,” says Tejin Cai, a postdoctoral researcher at York University and lead author on the Nature paper. Cai performed this research for his doctorate at the University of Rochester.

“The hydrogen and carbon are chemically bonded together, so the detector sees interactions on both at once. But then, I realized that the very nuclear effects that made scattering on carbon complicated also allowed us to select hydrogen and would allow us to subtract off the carbon interactions.”

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