Global CKM Fits with the Scan Method

Understand

We present results of a unitary triangle fit based on the scan method.

• This frequentist approach employs Gaussian uncertainties for experimental quantities, but makes no arbitrary assumptions about the distribution of theoretical errors.
• Instead, we perform a large number of fits, scanning over regions of plausible theory errors for each quantity, and retain those fits meeting a specific confidence level criterion, thereby constraining the $\bar \rho - \bar \eta $ plane using the standard input measurements (CKM matrix elements, $\sin2 \beta, B^0_{d,s}$ mixing, $\epsilon_K$) as well as branching fraction and \CP asymmetry measurements of B decays to $PP, PV, VV$, and $a_1 P$ final states to determine $\alpha$, $D^{(*)}K^{(*)}$ modes to determine $\gamma$, and $D^{(*)}\pi$ and $D\rho$ modes to determine $2\beta +\gamma$.
• We parameterize individual decay amplitudes in terms of color-allowed tree, color-suppressed tree, penguin, singlet penguin, electroweak penguin, as well as $W$-exchange and $W$-annihilation amplitudes.