====== Proton poliarizability ======

There are still many uncertainties regarding the inner workings of protons (and neutrons) See : [[content:physics:quantum_physics:proton_structure]].

Beginning in year 2000, a series of experiments began to show anomalies in the behaviour of the proton's sub-components (quarks and gluons) when exposed to strong magnetic and electric fields.

The anomalies concern the way the quarks and gluons can support (or resist) polarization.

>The visible world is founded on the proton, the only composite building block of matter that is stable in nature. Consequently, understanding the formation of matter relies on explaining the dynamics and the properties of the proton’s bound state.\\ [...]\\ Of particular interest is a puzzle in the electric generalized polarizability of the proton that remains unresolved after two decades. \\ [ Source below ]

The anomalous measurements cannot be explained by the currently accepted [[https://en.wikipedia.org/wiki/Quantum_chromodynamics|QCD]] (Quantum ChromoDynamics) model.

The lack of correlation between QCD calculations of how the proton //should// behave in intense fields, and how it actually //does// behave, suggests that : either QCD is an incomplete model, or there are other important inner-workings of the proton yet to be discovered.

>Together, the two components of the generalized polarizabilities provide a puzzling picture of the nucleon’s dynamics that emerge at long distance scales. The proton has the unique role of being nature’s only stable composite building block. Consequently, the observed anomaly in a fundamental system property comes with a unique scientific interest. It calls for further measurements so that the underlying dynamics can be mapped with precision and highlights the need for an improved theory so that a fundamental property of the proton can be reliably described.\\ [Source below]

For full technical details, see : 'Measured proton electromagnetic structure deviates from theoretical predictions' [[https://www.nature.com/articles/s41586-022-05248-1.epdf?sharing_token=bJvuEBdV_9Ph9VJ-zebszNRgN0jAjWel9jnR3ZoTv0MDy0Emq011SUjgw029hFkBILlr8XbUpySVa68nG75Sjv66pWCZCMyBmt311UQ8oNqzlUAt30DVrkBOWlCfGs1ba0Nix7VKiTcG9bpKkg0UmEQ5PkA7a6Da4mr-y2UZZUniDBaNRRBo3GVanYjPFniIG-jqJdmbx-hbCsSS2niQN9DOvvkAB61mPIPlLNGq7rc%3D|Nature]]{{:oa_padlock_grn.png?16}}2022 Oct 19, ahead of print.