Open charm meson production at BNL RHIC within k_(t)-factorization approach and revision of their semileptonic decays

We discuss inclusive production of open charm mesons in proton-proton scattering at the BNL RHIC. The calculation is performed in the framework of $k_t$-factorization approach which effectively includes higher-order pQCD corrections. Different models of unintegrated gluon distributions (UGDF) from the literature are used. We focus on UGDF models favoured by the LHC data and on a new up-to-date parametrizations based on the HERA collider DIS high-precision data. Results of the $k_t$-factorization approach are compared to next-to-leading order collinear predictions. The hadronization of heavy quarks is done by means of fragmentation function technique. The theoretical transverse momentum distributions of charmed mesons are compared with recent experimental data of the STAR collaboration at $\sqrt{s} = 200$ and $500$ GeV. Theoretical uncertainties related to the choice of renormalization and factorization scales as well as due to the quark mass are discussed. Very good description of the measured integrated cross sections and differential distributions is obtained for the Jung setB$0$ CCFM UGDF. Revised charm and bottom theoretical cross sections corresponding to those measured recently by the STAR and PHENIX collaborations for semileptonic decays of $D$ and $B$ mesons are presented. Significant improvement in theoretical description of the non-photonic electrons measurements is clearly obtained with respect to the previous studies within the $k_{t}$-factorization.