20 pagesInternational audienceWe provide a concise overview on transverse momentum dependent (TMD) parton distribution functions, their application to topical issues in high-energy physics phenomenology, and their theoretical connections with QCD resummation, evolution and factorization theorems. We illustrate the use of TMDs via examples of multi-scale problems in hadronic collisions. These include transverse momentum q_T spectra of Higgs and vector bosons for low q_T, and azimuthal correlations in the production of multiple jets associated with heavy bosons at large jet masses. We discuss computational tools for TMDs, and present an application of a new tool, TMDlib, to parton density fits and parameterizations

We find out the connection between the unintegrated gluon distribution at low intrinsic transverse momenta and the inclusive spectrum of the hadrons produced in pp collision at LHC energies in the mid-rapidity region and low hadron transverse momenta. The parameters of this distribution are found from the best description of the LHC data. Its application to the analysis of ep deep inelastic scattering allows us to obtain the results which describe reasonably well the H1 and ZEUS data on the structure functions at low x. A connection between the soft processes at LHC and small x physics at HERA has been found. PACS number(s): 12.38.-t, 13.85.-t

We present a unified approach to neutrino processes in nucleon matter based on Landau's theory of Fermi liquids that includes one-and two-quasiparticle-quasihole pair states as well as mean-field effects. We show how rates of neutrino processes involving two nucleons may be calculated in terms of the collision integral in the Landau transport equation for quasiparticles. Using a relaxation time approximation, we solve the transport equation for density and spin-density fluctuations and derive a general form for the response functions. We apply our approach to neutral-current processes in neutron matter, where the spin response function is crucial for calculations of neutrino elastic and inelastic scattering, neutrino-pair bremsstrahlung and absorption from strongly-interacting nucleons. We calculate the relaxation rates using modern nuclear interactions and including many-body contributions, and find that rates of neutrino processes are reduced compared with estimates based on the one-pion exchange interaction, which is used in current simulations of core-collapse supernovae.PACS numbers: 97.60. Bw, 26.50.+x, 95.30.Cq, I. INTRODUCTIONNeutrino emission, absorption and scattering processes in nucleon matter play a crucial role for the physics of stellar collapse, supernova explosions and neutron stars [1,2]. Since the leptons in these processes interact weakly, the neutrino rates can be expressed compactly in terms of the response of nuclear matter to axial and vector probes. In many situations, the axial response is the more important, and in this paper we concentrate on this case, which for a system of nonrelativistic nucleons amounts to the spin or spin-isospin response. These responses have been calculated by a number of groups [3,4,5,6,7] allowing for single nucleon quasiparticle-quasihole pair states. 1 However, this is insufficient for rates of neutrino processes involving two nucleons, such as neutrino-pair bremsstrahlung and absorption, and modified Urca reactions, in which two particle-hole pair states are necessary. The possible importance of two particle-hole pair states for neutrino inelastic scattering, in particular for energy exchange and the formation of the neutrino spectra, has been emphasized by Raffelt et al. [8,9,10]. Bounds on the magnitude of the two particle-hole pair weight have been investigated in Ref. [11] and it has been shown how the two-pair response is directly related to the collision term in Landau's transport equation for quasiparticles [12].Noncentral contributions to nuclear interactions, such as tensor forces from pion exchanges and spin-orbit forces, are essential for the two particle-hole pair response, as is clear from calculations of neutrino-pair bremsstrahlung and the modified Urca processes [13] and from general considerations based on conservation laws [11]. Neutrino-pair bremsstrahlung and absorption change the number of neutrinos and are key for equilibrating muon and tau neutrino number densities in supernovae. The standard rates for bremsstrahlung are based on the...

Despite rather long-term theoretical and experimental studies, 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 $\sqrt{s}=$ 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 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 the performed theoretical study it is demonstrated that the investigation of the intrinsic heavy quark contributions looks very promising at the LHC in processes such as $pp\rightarrow \gamma+ c(b)+X$.Comment: 13 pages, 6 figure

Hadron inclusive spectra in pp collisions are analyzed within the modified quarkgluon 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 shows 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.