Related papers: Estimating epsilon'/epsilon. A Review
The present theoretical status of the parameter for direct CP violation epsilon'/epsilon in the Standard Model is reviewed and compared with most recent experimental measurements of the same quantity. After collecting the basic expressions…
I give a detailed introduction into the theoretical formalism for epsilon'/epsilon, which measures direct CP-violation in K -> pi pi decays. The current status of hadronic matrix elements and the strange quark mass is discussed. Several…
The measurement of epsilon'/epsilon has left open several theoretical problems, the most important of which is an accurate calculation of the relevant hadronic matrix elements. Here we study the possibility of relating epsilon' to CP…
We review different definitions of the $\epsilon'$ parameter describing direct CP violation in neutral kaon decays, which was precisely measured in recent experiments, and point out the inconsistency of some of them due to a CPT constraint.…
The direct CP violation parameter Re(epsilon'/epsilon) has been measured from the decay rates of neutral kaons into two pions using the NA48 detector at the CERN SPS. With 3.3 million KL->pi0pi0 events collected during the 1998 and 1999…
The direct CP violation parameter Re(epsilon'/epsilon) has been measured from the decay rates of neutral kaons into two pions using the NA48 detector at the CERN SPS. The 2001 running period was devoted to collecting additional data under…
I shortly review the present status of the theoretical calculations of epsilon'/epsilon and the comparison with the present experimental results. I discuss the role of higher order chiral corrections and in general of non-factorizable…
The long-distance contributions to $K\to 2\pi$ amplitudes can be pinned down, using well established Chiral Perturbation Theory techniques. The strong S--wave rescattering of the two final pions generates sizeable chiral loop corrections,…
CP violation in the neutral kaon system is known to be dominated by the mixing of K0 and anti-K0. Direct CP violation in the 2 pion decays of neutral kaons has been a controversial subject over the last decade. A strong experimental effort…
Direct CP violation is studied in two pion decays of the neutral kaon. Using data collected in the first beam period in 1997, the result for the parameter Re(epsilon'/epsilon) is (18.5+/-4.5(stat)+/-5.8(syst))x10^(-4).
The CP parameters $\epsilon$ and $\epsilon'/\epsilon$ are calculated in the aspon model of spontaneous CP violation, a model which solves the strong CP problem. A new range for the scale of spontaneous breaking of CP is found. It is shown…
I give a short presentation of the theoretical prediction of epsilon-prime/epsilon. Short distance and especially long distance aspects of the computation is discussed. I consentrate on the general framework and the chiral quark model…
We review the present theoretical status of the CP violating ratio epsilon'/epsilon in the Standard Model (SM) and confront its estimates with the most recent data. In particular we review the present status of the most important parameters…
The quantity $\varepsilon'/\varepsilon$ measures direct CP violation in Kaon decays. Recent SM predictions show a $2.9\sigma$ tension with data, with the theoretical uncertainty dominating. As rapid progress on the lattice is bringing…
Experiments at CERN and Fermilab have been competing each other to improve the measurement of a CP violation parameter, epsilon'/epsilon. Fermilab KTeV-E832 recently announced their final result, Re(epsilon'/epsilon) = [19.2 +- 2.1] x…
We discuss direct $CP$ violation in the standard model by giving a new estimate of $\varepsilon'/\varepsilon$ in kaon decays. Our analysis is based on the evaluation of the hadronic matrix elements of the \mbox{$\Delta S =1$} effective…
We give the recent experimental results and theoretical analysis of CP violating ratio epsilon'/epsilon. The present status is discussed in the light of the standard model.
We overview the detailed analysis of epsilon'/epsilon within the Standard Model, presented in ref. 1. When all sources of large logarithms are considered, both at short and long distances, it is possible to perform a reliable Standard Model…
The low energy dynamics of QCD is investigated with special attention paid to the matching between QCD and chiral perturbation theory(ChPT), and also to some useful algebraic chiral operator relations which survive even when we include…
The ratio $\epsilon'/\epsilon$ measures the size of the direct CP violation in $K_L\to\pi\pi$ decays $(\epsilon^\prime)$ relative to the indirect one described by $\epsilon$ and is very sensitive to new sources of CP violation. As such it…