Up to now, the existence of intrinsic (or valence-like) heavy quark components of the proton distribution function has not yet been confirmed or rejected. We show that this hypothesis can be verified at experiments on the inclusive production of the
open strangeness (NA61) and at measurements of prompt photons or vector bosons accompanied by heavy flavour jets performed at LHC, CERN. Our theoretical study demonstrates that investigations of the intrinsic heavy quark contributions look very promising in hard processes like $pprightarrow K^pm+X$ and $pprightarrowgamma/Z/W +c(b)+X$. A possible observation of these components at the CBM, NICA experiments is discussed also.
We analyze the inclusive spectra of hadrons produced in $pp$ collisions at high energies in the mid-rapidity region within the soft QCD and perturbative QCD assuming the possible creation of the soft gluons at low intrinsic transverse momenta $k_t$.
From the best description of the LHC data we found the parametrization of the unintegrated gluon distribution which at low $k_t$ is different from the one obtained within the perturbative QCD.
Hadron inclusive spectra in pp collisions are analyzed within the modified quark-gluon string model including both the longitudinal and transverse motion of quarks in the proton in the wide region of initial energies. The self-consistent analysis sho
ws that the experimental data on the inclusive spectra of light hadrons like pions and kaons at ISR energies can be satisfactorily described at transverse momenta not larger than 1-2 GeV/c. We discuss some difficulties to apply this model at energies above the ISR and suggest to include the distribution of gluons in the proton unintegrated over the internal transverse momentum. It leads to an increase in the inclusive spectra of hadrons and allows us to extend the satisfactory description of the data in the central rapidity region at energies higher than ISR.
