Direct CP Violation in $K_L\to {\pi }^{+}{\pi }^{-}\gamma$

Abstract

CP violation due to interference between $K_L$ and $K_S$ decays into ${\pi }^{+}{\pi }^{-}\gamma$ is analyzed in the Standard Model. The CP-violating parameter ${\epsilon }_{+-\gamma }^{\prime }$, which is the difference between ${\eta }_{+-\gamma }$ and ${\eta }_{+-}$, receives dominant contributions from $K^0-{\bar{K}}^0$ mixing and the gluon penguin diagram; its magnitude is calculated to be $10^{-2}\epsilon$ at a typical region of the Dalitz plot. Genuine direct CP violation in $K_L\to {\pi }^{+}{\pi }^{-}\gamma$ decay originating from the electromagnetic penguin diagram is of order $10^{-4}\epsilon$.

Latex, 14 pages, ITP-SB-93-32, IP-ASTP-20-93

References in corpus (3)

• Generalized Dimensional Analysis
• Rare Kaon Decays in the $1/N_c$-Expansion
• The Chiral Anomaly in Non-Leptonic Weak Interactions

Cited by in corpus (6)

• CP violation in kaon decays
• Non-Leptonic Kaon Decays and the Chiral Anomaly
• Constraints on $s\to d\gamma$ from Radiative Hyperon and Kaon Decays
• Reanalysis of CP Violation in K_L -> pi^+ pi^- gamma
• Kaon decay interferometry as meson dynamics probes
• Radiative Kaon Decays $K^{\pm }\to {\pi }^{\pm }{\pi }^0\gamma$ and Direct CP Violation