Probing hadronic formation times with antiprotons in p+A reactions at AGS energies Original Research Article

The production of antiprotons in p+A reactions is calculated in a microscopic transport approach employing hadronic and string degrees of freedom (HSD). It is found that the abundancies of antiprotons as observed by the E910 Collaboration in p+A reactions at 12.3 GeV/c as well as 17.5 GeV/c can approximately be described on the basis of primary proton–nucleon and secondary meson–baryon production channels for all targets. The transport calculations demonstrate that the antiproton rapidity distributions for heavy targets are sensitive to the View the MathML source (or hadron) formation time in the nuclear medium. Within our analysis the data from the E910 Collaboration are reasonably described with a formation time of 0.4–0.8 fm/c in the hadron rest frame.