Speaker
Description
We present a comprehensive exploration of the on-shell Higgs mechanism using the massless-massive correspondence (MMC) applied to scattering amplitudes in the Standard Model. The MMC, integrated with power counting based on the $v/E$ expansion (where $v$ denotes the electroweak vacuum expectation value (VEV)), is derived from spinor splitting and energy scaling of massive amplitudes. For an $n$-point massive amplitude $\mathcal{M}_n$, its energy scaling is categorized as $[\mathcal{M}_n]_l \sim E^{4-n} (v/E)^{l}$, aligning it with an $(n+l)$-point massless amplitude $\mathcal{A}_{n+l} \sim [\mathcal{M}_n]_l$. The Higgs mechanism is reflected in all order matching ($l\geq0$). Notably, when $l > 0$, the additional $l$ Higgs bosons in $\mathcal{A}_{n+l}$ manifest as VEVs in the infrared (IR), thereby matching $\mathcal{A}_{n+l}$ to $[\mathcal{M}_n]_l$. This transition, elucidating how the surplus Higgs bosons at high energy contribute to VEVs at low energy, is called the on-shell Higgsing mechanism.
