$\mu - e$ Conversion With Four Generations

Understand

We study $\mu - e$ conversion with sequential four generations.

• A large mass for the fourth generation neutrino can enhance the conversion rate by orders of magnitude.
• We compare constraints obtained from $\mu - e$ conversion using experimental bounds on various nuclei with those from $\mu \to e \gamma$ and $\mu \to e\bar e e$.
• We find that the current bound from $\mu - e$ conversion with Au puts the most stringent constraint in this model.