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Quantum electrodynamics

A chink in the armour?

A measurement of the size of the proton, obtained using spectroscopy of an exotic atomic system, yields a result of unprecedented accuracy — but in disagreement with values obtained by previous methods.

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Figure 1


Figure 2: Size of the proton.


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Flowers, J. A chink in the armour?. Nature 466, 195–196 (2010).

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