arXiv subjects

O. V. Selyugin

Publications and source records attributed to O. V. Selyugin.

At least 37 records · Page 2Linked to original sources

arXiv2018

Odderon, HEGS model and LHC data

We show that the impact of the maximal odderon amplitude at t=0 and centre-of-momentum energy 13 TeV is small. We obtain a value of rho(t=0) at 13 TeV of the order of 0.12. The real part of the odderon amplitude grows like log(s/s0) at high energies, and is calculated from the analytic properties of the amplitude. In the framework of the HEGS model, taking the same intercept for the odderon and the pomeron leads to a good fit of the new LHC data at 13 TeV. We also show that the main effect of the odderon can be seen in the region of the diffraction minimum of the differential elastic cross section. The form and energy dependence of the odderon amplitude determined in the HEGS model reproduce the characteristics of the diffraction minimum at 7, 8 and 13 TeV.

hep-ph↗

arXiv2018

Statistical and systematical errors in analyses of separate experimental data sets in high energy physics

Different ways of extracting parameters of interest from combined data sets of separate experiments are investigated accounting for the systematic errors. It is shown, that the frequentist approach may yield larger $χ^2$ values when compared to the Bayesian approach, where the systematic errors have a Gaussian distributed prior calculated in quadrature. The former leads to a better estimation of the parameters. A maximum-likelihood method, applied to different "gedanken" and real LHC data, is presented. The results allow to choose an optimal approach for obtaining the fit based model parameters.

hep-ex↗

arXiv2017

Generelized parton distributions and the structure of the hadrons

The dependence of the hadron interaction on its structure is examined in the framework of the generelized parton distributions (GPDs). The x dependence of the GPDs is determined by the parton distribution functions (PDFs), which were obtained from the deep inelastic scattering. The analysis of the whole sets of experimental data on the electromagnetic form factors of the proton and neutron with taking into account many forms of PDFs, obtained by the different Collaborations, make it possible to obtain the special momentum transfer dependence of the GPDs. This permits us to obtain the electromagnetic and gravitomagnetic form factors of the nucleons. The impact parameter dependence of the proton and neutron charge and matter densities is examined. The elastic hadron scattering at high energies was analyzed in the framework of the model that takes into account both these form factors (electromagnetic and gravitomagnetic).

hep-ph↗

arXiv2017

Momentum transfer dependence of the hadron GPDs and Compton form factors

The generalized parton distributions (GPDs) of the meson and nucleon at small and large values of the momentum transfer were determined on the basis of the comparative analysis of different sets of experimental data of electromagnetic form factors of the proton and neutron, using the different sets of the parton distribution functions (PDFs). As a result, different form factors of the nucleons and meson were calculated. The t-dependence of these form factors was checked up in the description of the nucleon-nucleon and meson-nucleon elastic scattering and the differential cross sections of the real Compton scattering.

hep-ph↗

arXiv2017

The energy dependence of the diffraction minimum in the elastic scattering and new LHC data

The soft diffraction phenomena in the elastic proton-proton scattering are reviewed from the viewpoint of experiments at the LHC (TOTEM and ATLAS collaboration). In the framework of the High Energy Generalized Structure (HEGS) model the form of the diffraction minimum in the nucleon-nucleon elastic scattering in a wide energy region is analyzed. The energy dependences of the main characteristics of the diffraction dip are obtained. The numerical predictions at LHC energies are presented. The comparison of the model predictions with the new LHC data at $\sqrt{s}=13$ TeV is made.

hep-ph↗

arXiv2016

An Analysis of the New LHC Data through the Dispersion Relations

We analyse the tension between the (indirect) measurements of the total cross section, and show the impact of various assumptions on the extraction of the parameters from the elastic scattering amplitude, with a special attention to the total cross section. In particular, the determination of the phase of the elastic scattering amplitude will play an important role, and we shall study it via dispersion relations. We shall also examine the origin of the dependence on momentum transfer of the slopes of the different parts of the scattering amplitude in different models. We shall also give the results of another similar analysis based on a Regge-trajectory approach for the hadron scattering amplitude.

hep-ph↗

arXiv2015

High Energy Hadron Spin Flip Amplitude

The high energy part of the hadron spin flip amplitude is examined in the framework of the new high energy general structure (HEGS) model of the elastic hadron scattering at high energies. The different forms of the hadron spin flip amplitude are compared in the impact parameters representation. It is shown that the existing experimental data of the proton-proton and proton-antiproton elastic scattering at high energy in the region of the diffraction minimum and at large momentum transfer give support in the presence of the energy-independent part of the hadron spin flip amplitude with the momentum dependence proposed in the works by Galynskii-Kuraev.

hep-ph↗

arXiv2015

GPDs of the nucleons and elastic scattering at high energies

Taking into account the electromagnetic and gravitational form factors, calculated from a new set of $t $-dependent GPDs, a new model is built. The real part of the hadronic amplitude is determined only through complex $s$. In the framework of this model the quantitative description of all existing experimental data at $52.8 \leq \sqrt{s} \leq 1960 \ $GeV, including the Coulomb range and large momentum transfers ($0.0008 \leq |t| \leq 9.75 \ $GeV$^2$), is obtained with only $3$ fitting high energy parameters. The comparison with the preliminary data of the TOTEM Collaboration at an energy of $7$ TeV is made.

hep-ph↗

arXiv2015

Momentum transfer dependence of gpds

Based on the factorization representation of the General Parton Distributions (GPDs) the momentum transfer dependence was determined by the analysis of the different representations of parton distribution functions (PDFs) and all possible experimental data of the electromagnetic form factors of the proton and neutron. The obtained $t$-dependence of the GPDs is checked by analysis of the different hadronic reactions (including exclusive and elastic hadron scattering) in a wide energy region with minimum free fitting parameters.

hep-ph↗

arXiv2015

Nucleon structure and the high energy interactions

On the basis of the representation of the generalized structure of nucleons a new model of the hadron interaction at high energies is presented. The new t-dependence of the generalized parton distributions (GPDs) is obtained from the comparative analysis of different sets of the parton distribution functions (PDFs), based on the description of the whole sets of experimental data of electromagnetic form factors of the proton and neutron. Taking into account the different moments of GPDs of the hadron the quantitative descriptions of all existing experimental data of the proton-proton and proton-antiproton elastic scattering from $\sqrt{s} = 9.8$ GeV to $ 8 \ $ TeV, including the Coulomb range and large momentum transfers up to $-t=15$ GeV$^2$, are obtained with a few free fitting high energy parameters. The real part of the hadronic elastic scattering amplitude is determined only through complex $s$ satisfying the dispersion relations. The negligible contributions of the hard Pomeron and the presence of the non-small contributions of the maximal Odderon are obtained. The non-dying form of the spin-flip amplitude is examined as well. The structure of the Born term and unitarized scattering amplitude are analysed. It is shown that the Black Disk Limit for the elastic scatering amplitude is not reached at LHC energies. Predictions for LHC energies are made.

hep-ph↗

arXiv2014

The hadron structure and the description of the elastic scattering in a wide region of t and s

On the basis of the new high energy general structure (HEGS) model, which takes into account the different moments of the General Parton Distributions (GPDs) of the hadron, the quantitative descriptions of all existing experimental data from \sqrt{s} = 9.8 GeV to <= \sqrt{s} <= 7 TeV, including the Coulomb range and large momentum transfers up to -t=15 GeV^2, are obtained with only 3 free fitting high energy parameters. The real part of the hadronic amplitude is determined only through complex s satisfying the dispersion relations. The negligible contributions of the hard Pomeron and non-small contributions of the maximal Odderon is shown. Predictions for LHC energies are made.

hep-ph↗

arXiv2014

Models of parton distributions and the description of form factors of nucleon

The comparative analysis of different sets of the parton distribution functions (PDFs), based on the description of the whole sets of experimental data of electromagnetic form factors of the proton and neutron, is made in the framework of the model of t-dependence of the generalized parton distributions (GPDs) with minimum free parameters and some extending variants of the model. In some cases, a large difference in the description of electromagnetic form factors of nucleons with using the different sets of PDF are found out. The different variants of the flavor dependence of the up and down quark form factors are presented and discussed. The gravitation form factors, obtained with the different sets of PDF, are also calculated and the anomalous gravimagnetic moment is compared with the Equivalence Principle. The calculations of the differential cross sections of the real Compton scattering are presented.

hep-ph↗

arXiv2014

Total cross sections and $ρ$ at high energy

Analysis of the new experimental data obtained by the TOTEM Collaboration at LHC at $\sqrt{s} = 7 \ $TeV at small momentum transfer is presented. The impact of the different assumptions on the extraction of the parameters of the elastic scattering amplitude, especially on the size of the total cross sections, is examined. It is shown that the contribution of the Coulomb amplitude and Coulomb-hadron interference term should be taken into account in the analysis of the existing experimental data at small momentum transfer. Our new method of extracting the real part of the hadron scattering amplitude from experimental data shows the inconsistency of the size of $ρ=0.14$ to the parameters of the imaginary part of the hadron scattering amplitude obtained by the TOTEM Collaboration. The analysis of the data is compared with the similar analysis in the Regge approach for the hadron scattering amplitude.

hep-ph↗

arXiv2013

Flavor dependence of the spin-independent and spin-dependent parts of $GDPs(x,t, ξ=0)$

The different sets of PDF with the new form of t-dependence of generalized parton distributions (GPDs) were examined in the descriptions of the electromagnetic form factors of the proton and neutron. One of the purposes was to minimize the number of fitting parameters. We found that main flavor difference related to the spin-dependent of PDF incoming as part in GPDs. Hence, contrary to some other work, our result shows a little flavor dependence of the t-dependence of the $GPDs(x,t,ξ=0$).

hep-ph↗

arXiv2013

Problems of determination of σ_{tot} at the LHC

The analysis of the procedure of the determining the parameters of the hadron elastic scattering amplitude at high energy is presented. The exponential and non-exponential form of the scattering amplitude are taken into account. Especially, the impact of the real parts of the hadron scattering amplitude and electromagnetic hadron interaction on the determination of the total cross section is examined.

hep-ex↗

arXiv2013

Models of the hadron structure and Data of the TOTEM Collaboration

The region of the small and large momentum transfer is examined from a view point of the contribution of the different parts of the scattering amplitude, soft and hard pomeron, and odderon contribution. The new model taking into account the different moments of the General Parton Distribution of the hadron is presented. The comparison with the preliminary data of the TOTEM Collaboration at an energy of 7 TeV is made.

hep-ex↗

arXiv2013

The structure of nucleons and the description of the electromagnetic form factors

The comparison of different sets of PDFs structure functions with the description of the whole sets of experimental data of electromagnetic form factors of the proton and neutron is made in the frame work of our model of t-dependence of generalized parton distributions (GPDs) and some other models. It is shown that despite a small difference of the description of the inelastic processes by the different sets of PDF there is an essentially large difference in the description of electromagnetic form factors of the nucleons.

hep-ph↗

arXiv2013

Hard and soft pomerons in elastic nucleon scattering

An analysis of the possible contribution of the hard pomeron in elastic hadron scattering at LHC energies is made. It is shown that such a contribution has affected the shape of the differential cross section in the Coulomb-hadron interference region and in the dip region. On the basis of the new High-Energy General Structure (HEGS) model, the possible contributions of the hard pomeron are investigated. The predictions of the model at $8 \ $ TeV are discussed.

hep-ph↗