Chiral perturbation theory (ChPT) provides a systematic framework for low-energy hadronic interactions. Using the Young tensor technique, we construct complete CP-eigen bases of the meson-baryon chiral Lagrangian up to p5-order. Building on these bases, we compare the external source, conventional spurion, and systematic spurion methods for matching quark-level effective operators onto ChPT; the systematic spurion method requires a minimal set of spurions and remains applicable beyond dimension six. We then apply this framework to coherent elastic neutrino-nucleus scattering and derive new constraints on neutrino non-standard interactions and new-physics scales. This work establishes a complete chain from chiral operator construction to quark-hadron matching and low-energy new-physics applications.

Biography

Chuan-Qiang Song is currently a postdoctoral researcher at the HIAS-UCAS. He obtained his PhD degree (2026) from ITP-CAS. His research interests are chiral perturbation theory，neutrino physics and effective field theory. 

Inviter: Jiang-Hao Yu