A 1996 Analysis of the CP Violating Ratio epsilon'/epsilon

Abstract

We update our 1993 analysis of the CP violating ratio $\text{epe}$ in view of the changes in several input parameters, in particular the improved value of the top quark mass. We also investigate the strange quark mass $m_s$ dependence of $\text{epe}$ in view of rather low values found in the most recent lattice calculations. A simple scanning of the input parameters within one standard deviation gives the ranges: $-1.2\cdot 10^{-4}\le \text{epe}\le 16.0\cdot 10^{-4}$ and $0\le \text{epe}\le 43.0\cdot 10^{-4}$ for $\text{ms}(\text{mc})=150\pm 20\text{mev}$ and $\text{ms}(\text{mc})=100\pm 20\text{mev}$ respectively. If the experimentally measured numbers and the theoretical input parameters are used with Gaussian errors, we find $\text{epe}=(3.6\pm 3.4)\cdot 10^{-4}$ and $\text{epe}=(10.4\pm 8.3)\cdot 10^{-4}$ respectively. We also give results for $\mathrm{Im}{V}_{ts}^{\ast }{V}_{td}$. Analyzing the dependence of $\text{epe}$ on various parameters we find that only for $\text{ms}(\text{mc})\le 100\text{mev}$ and a conspiration of other input parameters, values for $\text{epe}$ as large as $(2-4)\cdot 10^{-3}$ and consistent with the NA31 result can be obtained.

Comments: 14 pages, LaTeX, 3 figures included