Equation 10 · Part 1 · The Vacuum Has a History: Symmetry Breaking as Speciation
Symbol U
What this part means
U is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Its job in the formula
U is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Full expression→Symbol U→Article meaning
The passage around this formula
…like the photon, had no longitudinal mode to have. Three of the electroweak sector’s four generators are broken this way, giving mass to the , , and ; the fourth, corresponding to the unbroken electromagnetic U(1) , is not, which is why the photon remains massless. Weinberg’s 1967 paper assembled this mechanism into the specific gauge theory of leptons that, combined with the analogous quark sector, became the electroweak part of the Standard Model tested at the LHC decades later [ 6 ] .
Learn the underlying idea
A function assigns an output to each allowed input. The expression f(x) means “apply f to x”.
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Sources cited in the surrounding passage
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