Search

We consider the experimental data on the production of strange Lambdas, and multistrange baryons (Xi, Omega), and antibaryons, on nuclear targets, at the energy region from SPS up to LHC, in the framework of the Quark-Gluon String Model. One remarkable result of this analysis is the significant dependence on the centrality of the collision of the experimental ratios bar(Xi)+/bar(Lambda) and bar(Omega)+/bar(Lambda) ratios in heavy-ion collisions, at SPS energies., Comment: 4 pages, 2 figures, 1 table Contribution to the 51th International Symposium on Multiparticle Dynamics (ISMD2022), Pitlochry, Scotland, UK, July 31st-August 5th (2022)

We consider the experimental data on yields of protons, strange $\Lambda^{\prime}$s, and multistrange baryons ($\Xi$, $\Omega$), and antibaryons production on nuclear targets, and the experimental ratios of multistrange to strange antibaryon production, at the energy region from SPS up to LHC, and compare them to the results of the Quark-Gluon String Model calculations. In the case of heavy nucleus collisions, the experimental dependence of the $\overline{\Xi}^+/\overline{\Lambda}$, and, in particular, of the $\overline{\Omega}^+/\overline{\Lambda}$ ratios, on the centrality of the collision, shows a manifest violation of quark combinatorial rules., Comment: 18 pages, 7 figures, 4 tables. Accepted for publication in Physical Review D

We expose the current experimental and theoretical situation of the interesting case of the production of phi mesons in up to very high energy collisions of hadrons on both nucleon and nuclear targets, and we present a quantitavely good theoretical description of the corresponding experimental data, based on the formalism of the well established Quark-Gluon String Model, that has proved to be valid for a wide energy range. All the available experimental data for phi-meson production in hadron-nucleon collisions on the spectra of secondary phi, and on the ratios of phi/pi(-) and phi/K(-) production cross sections, as well the corresponding ones for phi-meson production on nuclear targets, are considered. In particular, it is seen that the production of phi-mesons on nuclear targets presents unusually small shadow corrections for the inclusive density in the central rapidity region., Comment: 29 pages, 14 figures, 4 tables

We consider the experimental data on neutral Kstar-meson production on nucleon and nuclear targets. The Quark-Gluon String Model quantitatively describes the inclusive density in the midrapidity region, as well as the initial energy and A dependences of the produced Kstar-mesons., Comment: 19 pages, 8 figures, and 4 tables. arXiv admin note: text overlap with arXiv:1610.06039

The inclusive spectra of secondaries produced in soft (minimum-bias) p+Pb collisions at LHC energy are calculated in the frame of the Quark-Gluon String Model, by including the inelastic screening corrections (percolation effects). These effects are expected to be quite large at the very high energies, and they should drive down the spectra in the midrapidity region more than 2 times, at sqrt(sNN)=5 TeV., Comment: Contribution to the Proceedings of the Low-x Meeting 2017, ed by C. Royon et al., Bisceglie, near Bari (Italy), June 13th-18th, 2017 (6 pages and 1 table)

We consider the experimental data on phi-meson production on nuclear targets, and we find that they present unusually small shadow corrections for the inclusive density in the midrapidity region. We also give a quantitatively consistent description of both the initial energy dependence and the A-dependence of the produced phi-mesons, obtained in the frame of the Quark-Gluon String Model., Comment: 13 pages, 6 figures, and 3 tables. arXiv admin note: text overlap with arXiv:1604.01918

We calculate the inclusive spectra of secondaries produced in soft (minimum bias) p+Pb collisions in the framework of Quark-Gluon String Model at LHC energy, by taking into account the inelastic screening corrections (percolation effects). The role of these effects is expected to be very large at the very high energies, and they should decrease the spectra more than 2 times in the midrapidity region at sqrt(s)_(NN) = 5 TeV. The experimental data confirm such a picture, which means that the nuclear screening effects are connected with the Pomeron interaction rather than with the interactions of the produced secondary particles in the final state., Comment: 11 pages, 2 figures, and 2 tables. arXiv admin note: substantial text overlap with arXiv:1207.6900

The experimental data on p, Lambda, Xi-, Omega-, baryons and the corresponding antibaryons spectra obtained by different collaborations are compared with the results of the calculations performed into the frame of the Quark-Gluon String Model. The contribution of String Junction diffusion and the inelastic screening corrections are accounted for in the theoretical calculations. The predictions of the Quark-Gluon String Model both for pp and pA collisions are extended up to the LHC energies., Comment: 23 pages, 12 figures, and 3 tables. arXiv admin note: substantial text overlap with arXiv:1305.0388; text overlap with arXiv:1307.3442 by other authors

In this paper we present the description of the production of strange and mulistrange baryons in a wide energy region, from CERN SpS up to LHC, in the framework of the Quark-Gluon String model., Comment: Proceedings of Initial Stages 2014 Conference (6 pages, 2 figures, and 2 tables)

We consider the photoproduction of secondary mesons in the framework of the Quark-Gluon String model. At relatively low energies, not only cylindrical, but also planar diagrams have to be accounted for. To estimate the significant contribution of planar diagrams in gamma-p collisions at rather low energies, we have used the expression obtained from the corresponding phenomenological expression for pi-p collisions. The results obtained by the model are compared to the existing SLAC experimental data. The model predictions for light meson production at HERMES energies are also presented., Comment: 13 pages and 8 figures

We consider the experimental data on var(phi)-meson production in hadron-nucleon collisions for a wide energy region. The Quark-Gluon String Model quantitatively describes the spectra of secondary var(phi), as well as the ratios of var(phi)/pi^- and var(phi)/K^- production cross sections., Comment: 11 pages and 7 figures

We consider the experimental ratios of multistrange to strange antibaryon production and compare them to the standard Quark-Gluon String Model predictions. The significant differences between the experimental bar(Xi)+/bar(Lambda) and, especially, bar(Omega)+/bar(Lambda) values and model predictions can be interpreted as the signal of the existence of an additional source of multistrange antibaryon production. The possible connection of this additional source with Quark-Gluon Plasma (QGP) formation can turn the bar(Omega)+ production into a good QGP signature., Comment: 17 pages, 6 figures, and 3 tables. arXiv admin note: substantial text overlap with arXiv:1305.0388, arXiv:1207.6900

The experimental data on net proton and net Lambda-hyperon spectra obtained by the NA35 Collaboration, as well as the inclusive densities of Lambda and bar-Lambda obtained by NA49, NA57, and STAR collaborations, are compared with the predictions of the Quark-Gluon String Model. The contributions of String Junction diffusion, interactions with nuclear clusters, and the inelastic screening corrections are accounted for. The level of numerical agreement of the calculations with the experimental data is of about 20-30%. The predictions for LHC are also presented., Comment: 20 pages, 7 figures, and 1 table

We calculate the inclusive spectra of secondaries produced in soft (minimum bias) p+Pb collisions in the framework of Quark-Gluon String Model at LHC energy, and by taking into account the inelastic screening corrections (percolation effects). The role of these effects is expected to be very large at very high energies, and they should decrease the spectra about 3 times in the midrapidity region and increase them about 2 times in the fragmentation region at the energy of LHC., Comment: 18 pages and 10 figures. arXiv admin note: text overlap with arXiv:0802.2195

A significant asymmetry in baryon/antibaryon yields in the central region of high energy collisions is observed when the initial state has non-zero baryon charge. This asymmetry is connected with the possibility of baryon charge diffusion in rapidity space. Such a diffusion should decrease the baryon charge in the fragmentation region and translate into the corresponding decrease of the multiplicity of leading baryons. As a result, a new mechanism for Feynman scaling violation in the fragmentation region is obtained. Another numerically more significant reason for the Feynman scaling violation comes from the fact that the average number of cutted Pomerons increases with initial energy. We present the quantitative predictions of the Quark-Gluon String Model (QGSM) for the Feynman scaling violation at LHC energies and at even higher energies that can be important for cosmic ray physics., Comment: 21 pages, 11 figures, and 1 table. arXiv admin note: substantial text overlap with arXiv:1107.1615, arXiv:1007.3206

We consider the first LHC data for elastic pp scattering in the framework of Regge theory with multiple Pomeron exchanges. The simplest eikonal approach allows one to describe differential elastic cross sections at LHC, as well as pp and $\bar{p}p$ scattering at lower collider energies, on a reasonable level., Comment: 11 pages, 5 figures, and 1 table

A significant asymmetry in baryon/antibaryon yields in the central region of high energy collisions is observed when the initial state has non-zero baryon charge. This asymmetry is connected with the possibility of a baryon charge diffusion in rapidity space. Evidently, such a diffusion should decrease the baryon charge in the fragmentation region leading to the corresponding decrease of the multiplicity of leading baryons. As a result, a new mechanism for Feynman scaling violation in the fragmentation region is obtained. We present the quantitative predictions for the Feynman scaling violation at LHC energies and even at highier energies that can be important for cosmic ray physics., Comment: 17 pages and 9 figures

We consider the first LHC data for pp collisions in the framework of Regge phenomenology, and the Quark-Gluon String Model, and we present the corresponding predictions for both the integral cross sections and the inclusive densities of secondaries, that are determined by Pomeron exchange. All parameters were fixed long time ago for the description of the data at fixed target energies. The first measurements of the total inelastic cross section by ATLAS and CMS Collaborations are in agreement with our calculations. Also the inclusive densities measured in the central region are in agreement with our theoretical predictions on the accuracy level of about 10-15%., Comment: Contribution to the Proceedings of the Low-x Meeting 2011 (talk presented by Yu.M. Shabelski) 14 pages, 6 figures, and 4 tables

We consider the first LHC data for pp collisions in the framework of Regge theory. The integral cross sections and inclusive densities of secondaries are determined by the Pomeron exchange, and we present the corresponding predictions for them. The first measurements of inclusive densities in midrapidity region are in agreement with these predictions. The possible contribution of Odderon (Reggeon with alpha(Odd)(0) ~ 1 and negative signature) exchange to the differences in the inclusive spectra of particle and antiparticle in the central region could be significant at LHC energies. The first data of ALICE Collaboration are consistent with a very small Odderon contribution. Probably, further LHC data will definitely settle the question of the Odderon existence., Comment: 31 pages, 18 figures, and 6 tables

We describe the WA89 Collaboration experimental data on Lambda, Sigma(-), Sigma(+), Xi(-), and Omega(-) baryons, and bar(Lambda) and bar(Xi(+)) antibaryons production in Sigma(-) collisions with C and Cu targets at 345 GeV/c (sqrt(s_(Sigma N)) ~ 25.5 GeV) in the frame of the Quark-Gluon String Model. How the theoretical results compare to the experimental data is discussed. Finally, some relations among the values of the model parameters obtained with the help of quark combinatorics are presented., Comment: 18 pages, 13 figures, and 1 table.

We prove that the Tutte polynomial of a coloopless paving matroid is convex along the portions of the line segments x+y=p lying in the positive quadrant. Every coloopless paving matroids is in the class of matroids which contain two disjoint bases or whose ground set is the union of two bases of M*. For this latter class we give a proof that T_M(a,a) <= max {T_M(2a,0), T_M(0,2a)} for a >= 2. We conjecture that T_M(1,1) <= max {T_M(2,0), T_M(0,2)} for the same class of matroids. We also prove this conjecture for some families of graphs and matroids., Comment: 17 pages

Charm production in pp collisions is considered in the framework of perturbative QCD. The values of two parameters, the charm quark mass $m_c$ and the QCD scale mu^2, are determined from the comparison of the theoretical calculations with experimental data. The RHIC data on charm and beauty production are compared with the k_T-factorization approach predictions and with standard NLO QCD. The calculated results underestimate the STAR Collaboration data. The role of possible nuclear effects is discussed. The predictions for LHC energies are also given., Comment: 15 pages, 6 figures, and 3 tables

The information about sizes and nuclear density distributions in unstable (radioactive) nuclei is usually extracted from the data on interaction of radioactive nuclear beams with a nuclear target. We show that in the case of nucleus-nucleus collisions the values of the parameters depend rather strongly on the considered theoretical approach and on the assumption about the parametrization of the nuclear density distribution. The obtained values of root-mean-square radii (R_{rms}) for stable nuclei with atomic weights A = 12-40 vary by approximately 0.1 fm when calculated in the optical approximation, in the rigid target approximation, and using the exact expression of Glauber Theory. We present several examples of R_{rms} radii calculations using these three theoretical approaches and compare these results with the data obtained from electron-nucleus scattering., Comment: 14 Pages, 5 Figure, and 1 Table

We consider the possible contribution of Odderon (Reggeon with alpha_(Odd)(0) similar to 1 and negative signature) exchange to the differences in the total cross sections of particle and antiparticle, to the ratios of real/imaginary parts of the elastic pp amplitude, and to the differences in the inclusive spectra of particle and antiparticle in the central region. The experimental differences in total cross sections of particle and antiparticle are compatible with the existence of the Odderon component but such a large Odderon contribution seems to be inconsistent with the values of Re/Im ratios. In the case of inclusive particle and antiparticle production the current energies and/or accuracy of the experimental data don't allow a clear conclusion. It is expected that the LHC will finally solve the question of the Odderon existence., Comment: Lecture given by Yu.M. Shabelski at the XLIII PNPI Winter School on Physics, St.Petersburg, Russia, February 2009 (30 pages, 13 figures, and 9 tables)

We consider the possible contribution of Odderon (Reggeon with \alpha_{Odd}(0) \sim 1 and negative signature) exchange to the differences in the total cross sections of particle and antiparticle, to the ratios of real/imaginary parts of the elastic pp amplitude, and to the differences in the inclusive spectra of particle and antiparticle in the central region. The experimental differences in total cross sections of particle and antiparticle are compatible with the existence of the Odderon component but such a large Odderon contribution seems to be inconsistent with the values of Re/Im ratios. In the case of inclusive particle and antiparticle production the current energies and/or accuracy of the experimental data don't allow a clear conclusion., Comment: 24 pages, 12 figures, and 4 tables

The midrapidity inclusive densities of different secondaries are calculated in the framework of the Quark-Gluon String Model. The transfer of baryon number in rapidity space due to the gluon string junction propagation leads to a significant effect on the net baryon production. The numerical results are in reasonable agreement with RHIC experimental data., Comment: Contribution to the Proceedings of the XLIII Rencontres de Moriond: QCD and High Energy Interactions, La Thulile, Italy, 8-15 March 2008. Talk presented by C. Merino (4 pages and 2 figures)

We evaluate both the tau lepton energy loss produced by photonuclear interactions and the neutrino charged current cross section at ultra-high energies, both relevant to neutrino bounds with Earth-skimming tau neutrinos., Comment: Contribution to the Proceedings of the XLIII Rencontres de Moriond: QCD and High Energy Interactions, La Thulile, Italy, 8-15 March 2008. Talk presented by G. Parente (4 pages and 3 figures)

In the framework of Quark-Gluon String Model we calculate the inclusive spectra of secondaries produced in d+Au collisions at intermediate (CERN SPS) and at much higher (RHIC) energies. The results of numerical calculations at intermediate energies are in reasonable agreement with the data. At RHIC energies numerically large inelastic screening corrections (percolation effects) should be accounted for in calculations. We extract these effects from the existing RHIC experimental data on minimum bias and central d+Au collisions. The predictions for p+Au interactions at LHC energy are also given., Comment: 18 pages and 10 figures

We evaluate both the tau lepton energy loss produced by photonuclear interactions and the neutrino charged current cross section at ultra-high energies, relevant to neutrino bounds with Earth-skimming tau neutrinos, using different theoretical and phenomenological models for nucleon and nucleus structure functions. The theoretical uncertainty is estimated by taking different extrapolations of the structure function F2 to very low values of x, in the low and moderate Q2 range for the tau lepton interaction and at high Q2 for the neutrino-nucleus inelastic cross section. It is at these extremely low values of x where nuclear shadowing and parton saturation effects are unknown and could be stronger than usually considered. For tau and neutrino energies E=10^9 GeV we find uncertainties of a factor 4 for the tau energy loss and of a factor 2 for the charged current neutrino-nucleus cross section., Comment: 20 pages and 11 figures

We consider the phenomenological implications of the assumption that baryons are systems of three quarks connected through gluon string junction. The transfer of baryon number in rapidity space due to the string junction propagation is considered in detail. At high energies this process leads to a significant effect on the net baryon production in hN collisions at mid-rapidities. The numerical results for midrapidity inclusive densities of different secondaries in the framework of the Quark-Gluon String Model are in reasonable agreement with the experimental data. One universal value lambda ~ 0.25 for the strangeness suppression parameter correctly describes the yield ratios of Lambda/p, Xi/Lambda, and Omega/Xi. The predictions for pp collisions at LHC energies are also presented., Comment: 12 pages, 5 figures, and 1 table

The process of secondary baryon production in pi(+-)p collisions at high energies in the central and forward fragmentation regions is considered in the framework of the Quark-Gluon String Model. The contribution of the string-junction mechanism to the baryon production is analysed. The results of numerical calculations are in reasonable agreement with the experimental data on the Lambda/bar(Lambda) and p/bar(p)$ asymmetries., Comment: Contribution to the Proceedings of QCD@Work 2007, International Workshop on Quantum Chromodynamics, Theory and Experiment, Martina Franca-Valle d'Itria, Italy, June 16-20, 2007 (6 pages and 4 figures)

The RHIC data on charm production are compared with the kT-factorization approach predictions, both standard NLO QCD and FONLL. The calculated results underestimate the STAR Collaboration data. The role of possible nuclear effects is discussed., Comment: Talk given at the Ninth Workshop on Non-Perturbative Quantum Chromodynamics, Paris (France), June 4th-8th, 2007 (8 pages and 3 figures)

The asymmetry of strange baryon production in Kp interactions at high energies is considered in the framework of the Quark-Gluon String Model. The contribution of the String-Junction Mechanism to the strange baryon production is analysed., Comment: Contribution to the proceedings of the IV International Conference on Quarks and Nuclear Physics (QNP06), Universidad Complutense, Madrid (Spain), 5-10 June 2006 (2 pages with 2 figures)

The process of baryon production in K p collisions at high energies is considered in the framework of the Quark-Gluon String Model. The contribution of the string-junction mechanism to the strange baryon production is analysed. The results of numerical calculations are in reasonable agreement with the data on inclusive spectra of p, Lambda, bar{Lambda}, and on the bar{Lambda}/Lambda asymmetry. The predictions for Xi and Omega baryons are presented., Comment: 19 pages, 7 figures