Tracing CP-violation in Lepton Flavor Violating Muon Decays

Abstract

Although the Lepton Flavor Violating (LFV) decay ${\mu }^{+}\to e^{+}\gamma$ is forbidden in the Standard Model (SM), it can take place within various theories beyond the SM. If the branching ratio of this decay saturates its present bound [{\it i.e.,} Br$({\mu }^{+}\to e^{+}\gamma )\sim 10^{-11}$], the forthcoming experiments can measure the branching ratio with high precision and consequently yield information on the sources of LFV. In this letter, we show that for polarized ${\mu }^{+}$, by studying the angular distribution of the transversely polarized positron and linearly polarized photon we can derive information on the CP-violating sources beyond those in the SM. We also study the angular distribution of the final particles in the decay ${\mu }^{+}\to e_1^{+}{e}^{-}{e}_2^{+}$ where $e_1^{+}$ is defined to be the more energetic positron. We show that transversely polarized $e_1^{+}$ can provide information on a certain combination of the CP-violating phases of the underlying theory which would be lost by averaging over the spin of $e_1^{+}$.

6 pages, 2 figures

References in corpus (12)

• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• The Cosmological Parameters 2006
• Muon Decay and Physics Beyond the Standard Model
• Lepton-Flavor Violation via Right-Handed Neutrino Yukawa Couplings in Supersymmetric Standard Model
• $\mu \to e\gamma$ and $\mu \to 3e$ processes with polarized muons and supersymmetric grand unified theories
• Solid State Systems for Electron Electric Dipole Moment and other Fundamental Measurements
• $\mu \to e\gamma$ Search with Polarized Muons
• P and T Odd Asymmetries in Lepton Flavor Violating Tau Decays
• CP Violation in Production and Decay of Supersymmetric Particles
• A Concept for a High-Energy Gamma-ray Polarimeter
• Light Mesons and Muon Radiative Decays and Photon Polarization Asymmetry
• Exploring Complex Phases of the MSSM at Future Colliders

Cited by in corpus (8)

• Leptonic CP violation
• Probing leptonic CP phases in LFV processes
• A Window on the CP-violating Phases of MSSM from Lepton Flavor Violating Processes
• Time-reversal symmetry violation in several Lepton-Flavor-Violating processes
• CP violating phases in mu-e conversion
• Measuring CP-violating phases through studying the polarization of the final particles in $\mu \to eee$
• A Guide to Flavour Changing Neutral Currents in the Littlest Higgs Model with T-Parity
• Extracting the CP-violating phases of trilinear R-parity violating couplings from $\mu \to eee$