Production of antiprotons in the upper atmosphere by interacting primary cosmic rays

We calculate the (p) over bar background in the upper atmosphere which results when primary cosmic rays interact with air nuclei. Since the (p) over bar yield from p-nucleus and nucleus-nucleus interactions is not directly known from experiments, we derive these quantities by using a Monte Carlo simulation which is theoretically based on the dual parton model and which had been successfully applied to the description of hadron production in high energy collisions. Results on the calculated atmospheric (p) over bar background indicate a larger (p) over bar background than earlier estimates predicted, particularly at low energies.