Asymptotic regimes for hadron diffractive scatterings and coulomb interaction. Arguments for the black disk mode

Comparative analysis of the interplay of hadron and Coulomb interactions in $pp^\pm$ scattering amplitudes is performed in a broad energy interval, $\sqrt{s}=1-10^6$ TeV, for two extreme cases: for the asymptotic interactions of hadrons in black disk and resonant disk modes. The interactions are discussed in terms of the $K$-matrix function technique. In the asymptotic regime the real part of the hadronic amplitude is concentrated in both cases on the boundary of the disks in the impact parameter space but the LHC energy region is not asymptotic for the resonant disk mode that lead to a specific interplay of hadronic and coulombic amplitudes. For the $pp$ scattering at $\sqrt{s}\sim 10$ TeV an interplay of the hadron and Coulomb interactions in the resonant disk modes is realized in a shoulder in $d\sigma_{el}/d{\bf q}^2$ at ${\bf q}^2\sim 0.0025-0.0075$ GeV$^2$. The absence of such a shoulder in the data at 8 TeV can be considered as an argument against the resonant disk mode.Comment: 13 pages, 8 figure

Central production of lepton-antilepton pairs and heavy quark composite states in hadron diffractive collisions at ultrahigh energies

Central production of lepton-lepton pairs ($e^+e^-$ and $\mu^+\mu^-$) and heavy quark composite states (charmonia and bottomonia) in diffractive proton collisions (proton momenta transferred ${|\bf q_\perp}|\sim m/\ln s$) are studied at ultrahigh energies ($\ln{s}>>1$), where $\sigma_{tot}(pp^\pm)\sim\ln^N s$ with 1\la N\la 2. The $pp^\pm$-rescattering corrections, which are not small, are calculated in terms of the $K$-matrix approach modified for ultrahigh energies. Two versions of hadron interactions are considered in detail: the growth (i) $\sigma_{tot}(pp^\pm)\sim\ln^2 s$, $\sigma_{inel}(pp^\pm)\sim\ln^2 s$ within the black disk mode and (ii) $\sigma_{tot}(pp^\pm)\sim\ln^2 s$, $\sigma_{inel}(pp^\pm)\sim\ln s$ within the resonant disk mode. The energy behavior of the diffractive production processes differs strongly for these modes, thus giving a possibility to distinguish between the versions of the ultrahigh energy interactions.Comment: 10 pages. arXiv admin note: substantial text overlap with arXiv:1408.069

Non-strange and strange pentaquarks with hidden charm

Non-strange and strange pentaquaks with hidden charm are considered as diquark-diquark-antiquark composite systems. Spin and isospin content of such exotic states is discussed and masses are evaluated.Comment: 8 page