Global Fits of the CKM Matrix with the SCAN Method

TL;DR

This paper introduces a comprehensive scan method to analyze the CKM matrix, incorporating latest measurements and theoretical uncertainties without assumptions, confirming consistency with the Standard Model.

Contribution

It develops a novel scan approach for CKM analysis that accounts for all correlations and uncertainties, providing a robust Standard Model consistency check.

Findings

Data are consistent with the Standard Model.

No evidence for new physics contributions.

Correlations among CKM parameters are thoroughly analyzed.

Abstract

We present a Scan Method analysis of the allowed region of the rho bar - eta bar plane using the latest input measurements of the CKM matrix elements, sin 2 beta, B0(s,d) mixing, epsilon(K), alpha and gamma. In this approach, we make no assumptions as to the distribution of theory uncertainties; rather, we scan over the range of plausible theoretical uncertainties and determine confidence level contours in the rho bar eta bar plane. We determine alpha from branching fraction and CP asymmetry measurements of B decays to all light pseudoscalar-pseudoscalar, pesudoscalar-vector, vector-vector and a1-psudoscalar mesons and determine gamma from D(*)K(*), D(*) pi and D rho modes, thereby including correlations between the angles of the unitarity triangle. We parametrize the individual decay amplitudes in terms of color-allowed tree, color-suppressed tree, gluonic penguin, singlet penguin, electroweak penguin, as well as W-exchange and W-annihilation amplitudes. Our procedure accounts for all correlations among the fitted CKM parameters (rho bar, eta bar, A, lambda). The data are consistent with the Standard Model with no need for new physics contributions. We also examine example "wall plots", i.e., projections of sensitive parameters showing correlations among them and regions of preferred theoretical parameters.