====== Proton structure ======

The 'textbook' explanation for the structure of the proton is that it's a 'state' of two up quarks and one down quark bound by gluons, But it has been known for 40 years or so that this is an over-simplification. According to accepted quantum theory, there should also be infinite varying probabilities for the inclusion of quark–antiquark pairs.

A 2022 paper in //Nature//, from the [[http://nnpdf.mi.infn.it/|NNPDF Collaboration]], reports on experimental data which suggests the possibility that protons might also routinely feature a 'charm' quark and its antimatter equivalent, an 'anticharm'.

The research team suggest that around 0.5% of the proton's momentum (and by implication, its mass) might be coming from the charm / anticharm pair.

If confirmed, it would have broad-ranging and profound implications for nuclear physics research - as many other experiments heavily rely on an accurate model of the proton's internal structure.

See :  [[https://www.nature.com/articles/s41586-022-04998-2.pdf|Evidence for intrinsic charm quarks in the proton]] {{:oa_padlock_grn.png?16}}//Nature//, volume 608, pages 483–487 (2022)

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Also see : [[content:physics:quantum_physics:proton_mass]]

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