2026/07/31 by Chao-Qiang Geng, Chia-Wei Liu, Sheng-Lin Liu +1
Physics and Astronomy · #hep-ex #hep-ph
7 pages
arxiv created 2026/07/31 · arxiv published 2026/07/31 · arxiv updated 2026/08/03
We propose a new class of CP sum rules in the U-spin limit, based on the observation that the weak phase in the Standard Model can be removed in the degenerate limit md=ms. Unlike previous U-spin analyses formulated at the amplitude level, our sum rules are expressed directly in terms of decay widths. They apply to matched partial waves, spin observables, and angular moments and include nonpairwise cases beyond the usual single-insertion d↔ s relation.