Investigating $D^0$ meson production in p-Pb collisions at 5.02 TeV with a multi-phase transport model

We study the production of $$D^0$$D 0 meson in p+p and p-Pb collisions using the improved AMPT model considering both coalescence and independent fragmentation of charm quarks after the Cronin broadening is included. After a detailed discussion of the improvements implemented in the AMPT model for heavy quark production, we show that the modified AMPT model can provide a good description of $$D^0$$D 0 meson spectra in p-Pb collisions, the $$Q_{\textrm{pPb}}$$Q pPb data at different centralities and $$R_{\textrm{pPb}}$$R pPb data in both mid- and forward (backward) rapidities. We also studied the effects of nuclear shadowing and parton cascade on the rapidity dependence of $$D^{0}$$D 0 meson production and $$R_{\textrm{pPb}}$$R pPb . Our results indicate that using the same strength of the Cronin effect (i.e $$\delta $$δ value) as that obtained from the mid-rapidity data leads to a considerable overestimation of the $$D^0$$D 0 meson spectra and $$R_{\textrm{pPb}}$$R pPb data at high $$p_{\textrm{T}}$$p T in the backward rapidity. As a result, the $$\delta $$δ is determined via a $$\chi ^2$$χ 2 fitting of the $$R_{\textrm{pPb}}$$R pPb data across various rapidities. This work lays the foundation for a better understanding of cold-nuclear-matter (CNM) effects in relativistic heavy-ion collisions.