Low Energy Constants from Kl4 Form-Factors
G. Amor\'os (Lund U. & Helsinki U.), J. Bijnens, P. Talavera (Lund, U.)
TL;DR
This paper computes Kl4 decay form-factors to two-loop order in Chiral Perturbation Theory, updating the low-energy constants with improved precision and analyzing the uncertainties involved.
Contribution
It provides the first two-loop calculations of Kl4 form-factors and refines the values of ChPT low-energy constants at p^4 order.
Findings
Updated values for L's, the ChPT constants, are obtained.
Uncertainties in the low-energy constants are analyzed.
Comparison with previous estimates shows significant changes.
Abstract
We have calculated the form-factors F and G in K ---> pi pi e nu decays (Kl4) to two-loop order in Chiral Perturbation Theory (ChPT). Combining this together with earlier two-loop calculations an updated set of values for the L's, the ChPT constants at p^4, is obtained. We discuss the uncertainties in the determination and the changes compared to previous estimates.
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.