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High-energy physics

The mass question

Do the elementary particles known as neutrinos have mass? Yes, according to recent experiments. But how much? A surprising — and controversial — result suggests that the answer is not what we thought.

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Figure 1: The standard model of high-energy physics: fundamental particles and their masses (in GeV c−2, where c is the speed of light).
Figure 2: Chirality is the spice of life.


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Correspondence to Edward Witten.

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Witten, E. The mass question. Nature 415, 969–971 (2002).

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