New method for fitting coefficients in standard model effective theory
Abstract
We present an alternative method for carrying out a principal-component analysis of Wilson coefficients in standard model effective field theory (SMEFT). The method is based on singular-value decomposition (SVD). The SVD method provides information about the sensitivity of experimental observables to physics beyond the standard model that is not accessible in the Fisher-information method. In principle, the SVD method can also have computational advantages over diagonalization of the Fisher information matrix. We demonstrate the SVD method by applying it to the dimension-6 coefficients for the process of top-quark decay to a quark and a boson and use this example to illustrate some pitfalls in widely used fitting procedures. We also outline an iterative procedure for applying the SVD method to dimension-8 SMEFT coefficients.
Keywords
Cite
@article{arxiv.1912.09843,
title = {New method for fitting coefficients in standard model effective theory},
author = {Geoffrey T. Bodwin and Hee Sok Chung},
journal= {arXiv preprint arXiv:1912.09843},
year = {2020}
}
Comments
27 pages, 3 tables, minor clarifications, corrections, improvements in notation. Corresponds to published version