Revealing treacherous points for successful light-front phenomenological applications

Light-front dynamics (LFD) plays an important role in hadron phenomenology as evidenced from recent development of generalized parton distributions and other physical quantities involving hadrons. For the successful LFD applications to hadron phenomenology, however, treacherous points such as zero-mode contributions should be taken into account. For a concrete example of zero-mode contribution, we present Standard Model analysis of vector anomaly in the CP-even form factors of a W± gauge bosons. The main distinguished features of LFD are discussed in comparison with other Hamiltonian dynamics. We also present a power counting method to correctly pin down which hadron form factors receive the zero-mode contribution and which ones do not. Indications from our analysis to hadron phenomenology are discussed.