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Jonah Berean-Dutcher

Publications and source records attributed to Jonah Berean-Dutcher.

2 recordsLinked to original sources

Running soft theorems in effective field theory

We study soft theorems for photons and pions with local effective field theory (EFT) corrections up to one loop order. In massive QED with a dimension-five Pauli operator, the local analytic part of the subleading soft photon theorem is renormalized by the hard integration region. On the other hand, as was previously known, the logarithmic soft terms do not receive corrections from higher-dimensional operators. We find that analogous structure appears in the double-soft pion theorem: the coefficients of logarithmic contributions are controlled entirely by the Nonlinear Sigma Model (NLSM) Lagrangian, while the Wilson coefficients of four-derivative operators in Chiral EFT appear in local subleading terms, in a form that is dictated by their RG equations.

hep-th↗

Soft Theorems from Higher Symmetries

We describe the connection between spontaneously-broken higher symmetries and soft theorems for scattering amplitudes of their associated Nambu-Goldstone bosons. Our main result is a new sub-leading double soft pion theorem in theories with a spontaneously-broken continuous 2-group global symmetry, which intertwines amplitudes with different numbers of pions and photons. We also provide a novel derivation of the leading soft photon theorem from the Ward identity of an emergent 1-form global symmetry in effective field theories where antiparticles are integrated out. Our derivations of these soft theorems use the algebra of spacetime currents and do not rely on asymptotic symmetries or diagrammatic arguments.

hep-th↗