Our treatment of the electroweak interactions of massless leptons may be extended to massless quarks by invoking lepton€“quark symmetry between the doublets (ν_e, e^ˆ’) and (u, d) where we neglect quark mixing.

(a) What are the appropriate weak isospin and hyper charge quantum numbers (I³_W, Y^W) for u and d quarks in both left-handed and right handed states?

(b) Show that with these assignments, the unification condition (D.72) leads to the appropriate electromagnetic interactions for (u, d) quarks. 

Transcribed Image Text:

(D.72) e = g sin Ow = g' ' cos Ow gw sin Ow 9z cos Ow, 2/2