Antiproton production cross sections in cosmic rays

The cosmic-ray flux of antiprotons is measured with unprecedented accuracy bythe space-borne particle spectrometers AMS-02. Its interpretation requires acorrect description of the dominant production process for antiprotons in ourGalaxy, namely, the interaction of cosmic-ray proton and helium with theinterstellar medium. In the light of new cross section measurements by the NA61experiment of $p + p → \overline{p} + X$ and the first ever measurement of $p + He → \overline{p} + X$ by the LHCb experiment, we update the parametrization of proton-proton andproton-nucleon cross sections. By using $pp$, $p$He and $p$C data we estimate theuncertainty on the Lorentz invariant cross section for all relevant antiprotonproduction channels in the Galaxy. We use these new cross sectionparametrizations to compute the antiproton source term. The uncertainties on thetotal source term are up to $±20$% at low energies. Since this exceeds theuncertainties on the antiproton flux which is measured by AMS-02 at an accuracyof 5%, we finally quantify the necessity of new data on antiproton productioncross sections, and pin down the kinematic parameter space which should becovered by future data.