  We discuss kinematical correlations between charged leptons from semileptonic
decays of open charm/bottom, leptons produced in the Drell-Yan mechanism as
well as some other mechanisms not included so far in the literature in
proton-proton scattering at BNL RHIC. The distributions of charm and bottom
quarks/antiquarks are calculated in the framework of the $k_t$-factorization
approach. For this calculation we use the Kwieci\'nski unintegrated parton
distributions. The hadronization of heavy quarks is done by means of Peterson
et al. fragmentation function. We use semileptonic decay functions found by
fitting recent semileptonic data obtained by the CLEO and BABAR collaborations.
The Drell-Yan processes were calculated including transverse momenta of quarks
and antiquarks, also using the Kwieci\'nski parton distributions. We have also
took into consideration reactions initiated by purely QED
$\gamma^*\gamma^*$-fusion in elastic and inelastic pp collisions as well as
recently proposed diffractive mechanism of exclusive charm-anticharm
production. The contribution of the later mechanism is rather small. We get
good description of the dilepton invariant mass spectrum measured recently by
the PHENIX collaboration and present predictions for the dilepton pair
transverse momentum distribution as well as distribution in azimuthal angle
between electron and positron.
