Master formula for $\varepsilon'/\varepsilon$ beyond the Standard Model
arXiv:1807.02520 · doi:10.1016/j.physletb.2019.04.016
The authors derive a master formula for the direct CP‑violation ratio ε'/ε in K→ππ decays that is applicable to any beyond‑Standard‑Model scenario, using recent hadronic matrix elements from Dual QCD and lattice QCD and provide an implementation in the flavio package.
Abstract
We present for the first time a master formula for $\varepsilon'/\varepsilon$, the ratio probing direct CP violation in $K \to ÏÏ$ decays, valid in any theory beyond the Standard Model (BSM). The formula makes use of hadronic matrix elements of BSM operators calculated recently in the Dual QCD approach and the ones of the SM operators from lattice QCD. We emphasize the large impact of several scalar and tensor BSM operators in the context of the emerging $\varepsilon'/\varepsilon$ anomaly. We have implemented the results in the open source code flavio.
6 pages, 1 table. v3: signs in table I corrected. arXiv admin note: text overlap with arXiv:1808.00466