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Particles and Forces. Bosons. Chiral . For m=0 the helicity and the chirality are the same. The form of the spinor for m=0 maintains the strict relationship between the spin direction and the action of the gamma-5 matrix. In the limit of quark mass 0 there is a chiral symmetry for quarks.
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Chiral For m=0 the helicity and the chirality are the same. The form of the spinor for m=0 maintains the strict relationship between the spin direction and the action of the gamma-5 matrix. In the limit of quark mass 0 there is a chiral symmetry for quarks
U(1) • Define a property characterized by a single value. • E.G. Objects color • Change it uniformally (globally) without changing physics • Change is QM change of phase
SU(2) • Mixture of two things • Same as misture of spin ½ z-components • Equivalent to a rotation in a internal 3-4 space. • Changes the direction of the axis of quantization.
Local • Transformation depends on position