The proton structure function and a soft Regge Dipole Pomeron: a test with recent data

A recently published soft Regge Dipole Pomeron model intended for all $x$ and $Q^2$ is proved to give a good agreement with (non fitted) recent HERA data from ZEUS (SVX95) on the protonstructure function $F_2^p(x,Q^2)$ at low $Q^2$ and low $x$. The model also reproduces (without fit) the recently estimated experimental derivatives ${\partial F_2^p\over\partial\ell n Q^2}$ and ${\partial \ell n F_2^p\over\partial\ell n (1/x)}$ in a wide $x$ and $Q^2$-region.Comment: 5 pages (LaTeX), 4 figures (Encapsulated PS

New possibilities of old soft pomeron in DIS

A traditional Regge model with a $Q^2$-independent Pomeron intercept closed (or equal) to one is constructed in order to describe the available data on the proton structure function. A Dipole Pomeron model which does not explicitly violate unitarity is developed and investigated. An excellent agreement with the 1209 data is found ($\chi^2/{dof}=1.11$) in the whole kinematical domain investigated by experiments. A comparison of the model with already existing ones is made. The $x-$, $Q^2-$slopes and the effective intercept are discussed as $Q^2$ and $x$ functions.Comment: 19 pages LaTeX, 10 eps figures included, one of figure captions is correcte

Nonlinearities and Pomeron Nonfactorizability in Conventional Diffraction

Alternatives for describing the nonlinear behavior of the first diffraction cone in differential $pp$ and $\bar pp$ elastic cross-section are investigated. High quality fits to the data are presented. We show that the presence in the Pomeron amplitude of two terms with different $t$ dependences is strongly suggested by the data, hinting at a non-factorizable Pomeron even in the field of purely hadronic reactions. The available data, however, do no allow to choose among a nonlinearity in the residues or in the Pomeron trajectory or in both. In all cases, we find an effective slope of the trajectory larger than the one currently used. A nonlinear trajectory with the fitted parameters is used for predicting the mass and the width of the 2$^{++}$ glueball. An excellent agreement is found with the X(1900) candidate from the WA91 experiment.Comment: Plain TeX, 24 pages, 6 eps figures, to be published in Nuovo Ciment

Unified Model for Small-t and High-t Scattering at High Energies: Predictions at RHIC and LHC

The urgency of predictions in large-t region at LHC stimulated us to present a unified model of small and high t scattering at high energies. Our model is based upon a safe theoretical ground: analyticity, unitarity, Regge behavior, gluon exchange and saturation of bounds established in axiomatic quantum field theory. We make precise predictions for the behavior of the differential cross sections at high t, the evolution of the dip-shoulder structure localized in the region of -t between 0.5 and 0.8 GeV**2 and the radical violation of the exponential behavior of the first diffraction cone at small t.Comment: 6 pages, 2 table, 7 figures. Misprints are correcte

What do experimental data "say" about growth of hadronic total cross-section?

We reanalyse $\bar p p$ and $pp$ high energy data of the elastic scattering above $\sqrt{s}=5$ GeV on the total cross-section $\sigma_{tot}$ and on the forward $\rho$-ratio for various models of Pomeron, utilizing two methods. The first one is based on analytic amplitudes, the other one relies on assumptions for $\sigma_{tot}$ and on dispersion relation for $\rho$. We argue that it is not possible, from fitting only existing data for forward scattering, to select a definite asymptotic growth with the energy of $\sigma_{tot}$. We find equivalent fits to the data together with a logarithmic Pomeron giving a behavior $\sigma_{tot} \propto \ln ^\gamma s$, $\gamma\in [0.5,2.20]$ and with a supercritical Pomeron giving a behavior $\sigma_{tot} \propto s^\epsilon$, $\epsilon\in [0.01,0.10]$.Comment: LaTeX, 18 pages, 5 eps figures included, to be published in Il Nuovo Ciment

Associative production of B_c and D mesons at LHC

It is shown that the study of correlations in the associative production of B_c and D mesons at LHC allows to obtain the essential information about the B_c production mechanism.Comment: 14 pages, 10 figures. Some misprints have been removed in the last version. The reference to CTEQ pdf has been adde

Elastic pppp and pˉp\bar pp scattering in the models of unitarized pomeron

Elastic scattering amplitudes dominated by the Pomeron singularity which obey the principal unitarity bounds at high energies are constructed and analyzed. Confronting the models of double and triple (at $t=0$) Pomeron pole (supplemented by some terms responsible for the low energy behaviour) with existing experimental data on $pp$ and $\bar pp$ total and differential cross sections at $\sqrt{s}\geq 5$ GeV and $|t|\leq 6$ GeV$^{2}$ we are able to tune the form of the Pomeron singularity. Actually the good agreement with those data is received for both models though the behaviour given by the dipole model is more preferable in some aspects. The predictions made for the LHC energy values display, however, the quite noticeable difference between the predictions of models at $t\approx -0.4$ GeV$^{2}$. Apparently the future results of TOTEM will be more conclusive to make a true choice.Comment: Revtex4, 8 pages, 5 figures. Text is improved, no changes in figures and conclusions. Version to be published in Phys. Rev.