A calculation of the inclusive spectra of pions and kaons produced in
pp
collisions as functions of their transverse momentum
p
T
at mid-rapidity is presented within the self-similarity approach. A ...satisfactory description of the data within a wide range of initial energies is presented. We focus mainly on the ratio of cross-sections of
K
±
to
π
±
mesons produced in
pp
collisions as a function of
s
. A fast rise of this ratio, when the initial energy increases starting from the kaon production threshold up to
s
≃
20–30 GeV, is revealed together with its very slow increase up to LHC energies. The energy dependence of this ratio is due to the conservation laws of four-momenta and quantum numbers of the initial and produced hadrons. The more or less satisfactory agreement of these ratios with NA61/SHINE, RHIC and LHC data is demonstrated.
Despite rather long-term theoretical and experimental study, the hypothesis of the non-zero intrinsic (or valence-like) heavy quark component of the proton distribution functions has not yet been ...confirmed or rejected. The LHC with pp-collisions at s=7–14 TeV will obviously supply extra unique information concerning the above-mentioned component of the proton. To use the LHC potential, first of all, one should select the parton-level (sub)processes (and final-state signatures) that are the most sensitive to the intrinsic heavy quark contributions. To this end inclusive production of c(b)-jets accompanied by photons is considered. On the basis of performed theoretical study it is demonstrated that investigation of the intrinsic heavy quark contributions looks very promising at the LHC in processes like pp→γ+c(b)+X.
We study the role of the nonperturbative input to the transverse momentum dependent (TMD) gluon density in hard processes at the LHC. We derive the input TMD gluon distribution at a low scale ...(ProQuest: Formulae and/or non-USASCII text omitted) from a fit of inclusive hadron spectra measured at low transverse momenta in pp collisions at the LHC and demonstrate that the best description of these spectra for larger hadron transverse momenta can be achieved by matching the derived TMD gluon distribution with the exact solution of the Balitsky-Fadin-Kuraev-Lipatov equation obtained at low x and small gluon transverse momenta outside the saturation region. Then, we extend the input TMD gluon density to higher mu super(2) numerically using the Catani-Ciafoloni-Fiorani-Marchesini gluon evolution equation. Special attention is paid to phenomenological applications of the obtained TMD gluon density to some LHC processes, which are sensitive to the gluon content of a proton.
Dielectron production in the π
N
interaction at not large energies is studied assuming that the electron- positron pair is produced from splitting of the virtual time-like photon. It allows us to get ...the interesting information on a nucleon form factor in the time-like region of four momentum transfer squared. The dominant contribution of the Δ-isobar creation in the intermediate state at incident pion momenta of about 0.3–0.4 GeV/
c
is shown. The experimental distributions over the angle and effective mass
M
e
+
e
−
of the
e
+
e
−
pair are described satisfactorily. This stimulated us to present theoretical predictions for the
M
e
+
e
−
distribution in the process π
−
p
→
ne
+
e
−
at different incident momenta, which could be verified, for example, by the HADES experiments.
Changes in the transverse momentum distributions with beam energy are studied using the Tsallis distribution as a parameterization. The dependence of the Tsallis parameters q, T and the volume are ...determined as a function of beam energy. The Tsallis parameter q shows a weak but clear increase with beam energy with the highest value being approximately 1.15. The Tsallis temperature and volume are consistent with being independent of beam energy within experimental uncertainties.
We investigate the dependence of the deep inelastic proton structure function FL(x,Q2) on different forms of the transverse momentum dependent (TMD, or unintegrated) gluon distribution. We present a ...comparison of theoretical results with the latest experimental data taken by the H1 and ZEUS Collaborations at HERA. We demonstrate that these data, despite of having quite large uncertainties, can test different kinds of the gluon TMD in a proton. Moreover, different phenomenological models at low x could be tested by future experiments on deep inelastic scattering.
Using the analytical expression for transverse momentum dependent (TMD) gluon density in a proton, a self-consistent simultaneous description of low Q2 data on proton structure function F2(x,Q2), ...reduced cross section for the electron-proton deep inelastic scattering at HERA and soft hadron production in pp collisions at the LHC is achieved in the framework of color dipole approach and modified quark-gluon string model.
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