A Brane-World Explanation of the KARMEN Anomaly

Motivated by the anomaly in the KARMEN experiment, we study new possibilities for brane-world models of neutrino masses. We show that the KARMEN anomaly can be understood in the context of a six-dimensional brane-world model. The fine-tuning problem associated with the single-particle interpretation of the anomaly is thereby alleviated. Our model shows some interesting properties of general interest for brane-world neutrino physics. In particular, the size of the brane-bulk mixing decouples from the scales relevant for atmospheric and solar neutrino oscillations.