Does the positron 'excess' really exist?

The positron “excess” measured by two independent space missions and linked by some physicists to dark matter or pulsars does not exist, according to new theoretical work done by an international team of researchers. Instead, the researchers have calculated a "robust" upper limit for the positron flux created via interactions of high-energy cosmic rays with ambient gas in the galaxy and say that the flux measured by the Payload for Antimatter/Matter Exploration and Light-nuclei Astrophysics (PAMELA) experiment and the Alpha Magnetic Spectrometer (AMS) lies below this limit.