{'fraction_non_alphanumeric': 0.029914529914529916, 'fraction_numerical': 0.0017094017094017094, 'mean_word_length': 5.970238095238095, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Analysis of subthreshold antiproton production in p-nucleus and nucleus-nucleus collisions in the relativistic Boltzmann-Uehling-Uhlenbeck approach.

We calculate the subthreshold production of antiprotons in the Lorentz-covariant relativistic Boltzmann-Uehling-Uhlenbeck (RBUU) approach employing a weighted testparticle method to treat the antiproton propagation and absorption nonperturbatively. We find that the antiproton differential cross sections are highly sensitive to the baryon and antiproton self-energies in the dense baryonic environment. Adopting the baryon scalar and vector self-energies from the empirical optical potential for proton-nucleus elastic scattering and from Dirac-Brueckner calculations at higher density [rho][gt][rho][sub 0] we examine the differential antiproton spectra as a function of the antiproton self-energy. A detailed comparison with the available experimental data for [ital p]-nucleus and nucleus-nucleus reactions shows that the antiproton feels a moderately attractive mean field at normal nuclear matter density [rho][sub 0] which is in line with a dispersive potential extracted from the free annihilation cross section.