Speaker
Description
We discuss production of $D$ mesons at high and low energies. The cross section at high-energies is calculated in the $k_t$-factorization or standard (collinear) pQCD approach. The unintegrated gluon distributions are the main ingredient of the $k_t$-factorization approach. Several distributions, in rapidity, transversemomentum, are calculated. The asymmetries observed in production of $D^+ D^-$ and $D_s^+ D_s^-$ mesons observed recently by the LHCb collaboration call for deeper understanding. One of a possibility is nonperturbative light quark/antiquark subleading fragmentation. We have shown that a small amount of such processes, necessary to understand the LHCb asymmetries, may lead to dramatic effects at lower energies or in very forward/backward directions at high-energies. This may also have important implications for high-energy neutrinos observed by IceCube Observatory. Some fixed-target future experiments and relevant predictions will be discussed. I will also discuss production of $\Lambda_c$ baryons and show difficulties to understand it within independent charm quark/antiquark fragmentation picture.
