Rubin-LSST

Abstract:

We report on a study of the invariant mass spectrum of the hadronic system in the decay τ-→π-π0ντ. This study was performed with data obtained with the CLEO II detector operating at the CESR e+e- collider. We present fits to phenomenological models in which resonance parameters associated with the ρ(770) and ρ(1450) mesons are determined. The π-π0 spectral function inferred from the invariant mass spectrum is compared with data on e+e-π+π- as a test of the conserved vector current theorem. We also discuss the implications of our data with regard to estimates of the hadronic contribution to the muon anomalous magnetic moment. ©2000 The American Physical Society.

Abstract:

Relativistic outflows or "jets" are collimated streams of high-energy electrons that emit synchrotron radiation at radio wavelengths and have bulk velocities that are a substantial fraction of the speed of light. They trace the outflow of enormous amounts of energy and matter from a central supermassive black hole in distant radio galaxies. As Fender explains in this Perspective, much smaller, more local sources may also produce such jets. Data presented by Paredes et al. point toward association of one such source, a relatively faint x-ray binary, with a gamma-ray source. This and similar pairs may contribute substantially to the production of high-energy particles and photons within our galaxy.