The discussion focuses on checking the invariance of terms in the Standard Model (SM) Lagrangian under the symmetries SU(3) x SU(2) x U(1). To determine gauge invariance, one must verify that each term in the Lagrangian is in the trivial representation of the SM gauge groups. If a term is in the trivial representation, it is gauge invariant; otherwise, it is not. This process is essential for ensuring the consistency of the Lagrangian with the symmetries of the Standard Model.
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You have to ensure that any of the terms entering the Lagrangian is in the trivial representation of the SM gauge groups. If they are, then the term is gauge invariant. If not it is not.zaman786 said:TL;DR Summary: how can we check symmetry of SM in terms of Lagrangian
Hi, as we know SM is symmetric under SU(3) X SU(2) X U(1) , But my question is , how can we check the invariance of terms in Lagrangian under these symmetries - thanks
ok- got it - thanksOrodruin said:You have to ensure that any of the terms entering the Lagrangian is in the trivial representation of the SM gauge groups. If they are, then the term is gauge invariant. If not it is not.