Abstract
We propose a method for determining the mass difference between two particles, and , that are nearly degenerate, with . This method applies when (a) the momentum can be measured, (b) can only decay to , and (c) and can be produced in the decays of a common mother particle. For small , cannot be reconstructed directly, because its decay products are too soft to be detected. Despite this, we show that the existence of can be established by observing the shift in the mother particle invariant-mass peak, when reconstructed from decays to . We show that measuring this shift would allow us to extract . As an example, we study supersymmetric gauge-gravity hybrid models in which is a metastable charged slepton next-to-lightest supersymmetric particle and is the next-to-lightest slepton with .
- Received 1 July 2009
DOI:https://doi.org/10.1103/PhysRevD.80.114004
©2009 American Physical Society