Chiral Perturbation Theory for Non-local Matrix Elements at Subleading Power

Jack Jenkins (U of Siegen)

Aug 27. 2026, 11:30 — 12:10

The breakdown of a complete factorization of non-perturbative physics into soft and collinear matrix elements is a generic feature of Soft-Collinear Effective Theory (SCET) at subleading power. I will present a chiral effective theory for the resulting non-local matrix elements, obtained by matching multi-local SCET operators onto hadronic degrees of freedom with a local realization of chiral symmetry. After introducing the degrees of freedom and power counting of the theory, I will discuss its application to the soft-overlap contribution to $B \to \pi$ form factors, where it predicts a qualitatively different pattern of chiral corrections from hard-pion chiral perturbation theory, including a non-factorization of the pion-mass and recoil-energy dependence. Finally, I will discuss how the hadronic effective theory provides an infrared description of the physics underlying rapidity singularities.

Further Information
Venue:
ESI Schrödinger Lecture Hall
Associated Event:
New Paradigms for Harnessing Quantum Field Theory at Colliders (Thematic Programme)
Organizer(s):
Alessandro Broggio (U of Vienna)
André H. Hoang (U of Vienna)
Bianka Meçaj (LANL, Los Alamos)
Simon Plätzer (U of Graz)
Massimiliano Procura (U of Vienna)
Rudi Rahn (U of Vienna)
Malin Sjödahl (Lund U)
Iain W. Stewart (MIT, Cambridge)