arXiv subjects
Publications and source records attributed to O. V. Selyugin.
A new method for the determination of the real part of the elastic scattering amplitude is examined for high energy proton-proton and proton-nuclei elastic scattering at small momentum transfer. This method allows to decrease the number of model assumptions, to obtain the real part in the narrow region of momentum transfer and to test different models for hadron-nuclei scattering.
Through a direct analysis of the scattering amplitude, we show that the preliminary measurement of the analysing power AN obtained by the E950 Collaboration at different energies are mainly sensitive to the spin-flip part of the amplitude in which the proton scatters with the carbon 12 nucleus as a whole. The imaginary part of this amplitude is negative, and the real part positive. We give predictions for pL = 600 GeV/c, which depend mainly on the size of the real part of the amplitude.
The momentum-transfer dependence of the slopes of the spin-non-flip and spin-flip amplitudes is analysed. It is shown that the long tail of the hadronic potential in impact parameter space leads for hadron-hadron interactions to a larger value of the slope for the reduced spin-flip amplitude than for the spin-non-flip amplitude. It is shown that the preliminary measurement of AN obtained by the E950 Collaboration confirms such a behaviour of the hadron spin-flip amplitude.
Integral and derivative dispersion relations (DR) are considered for the forward scattering $pp$ and $\bar pp$ amplitudes. A new representation for the derivative DR, valid not only at high energy, is obtained. The data on the total cross sections for $pp (\bar pp)$ interaction as well as the data on the parameter $ρ$ are analyzed within the various forms of the DR and high-energy Regge models. It is shown that three models for the Pomeron, Simple pole Pomeron, Tripole Pomeron and Dipole Pomeron (the both with the intercept equal unit) lead to practically equivalent description of the data at $\sqrt{s}>$5 GeV. It is also shown that the correctly calculated low-energy part of the dispersion integral (from the two-proton threshold up to $\sqrt{s}=$5 GeV) allows to reproduce well the $ρ$ data at low energies without additional free parameters.
The effects of saturation and unitarization for hadron-hadron scattering at LHC energies are explored in several models. It is shown that different choices of saturation parameters lead to sizable differences in the energy dependence of total cross sections, and to dramatic changes in elastic differential cross sections.
Integral and derivative dispersion relations (DR) are considered for the $pp$ and $\bar pp$ forward scattering amplitudes. A new representation for the derivative DR, valid at lower energies than the standard one, is obtained. The data on the total cross sections of $pp (\bar pp)$ interaction as well as those on the ratio of the real part to the imaginary part of the forward amplitude are analyzed within various forms of the DR and high-energy Regge models. It is shown that three models for the pomeron, simple pole with intercept larger than one, triple pole pomeron and double pole pomeron (both with intercept equal to one) lead to practically equivalent descriptions of the data at $\sqrt{s}>5$ GeV. It is also shown that the low-energy part of the dispersion integral (from the two-proton threshold up to $\sqrt{s}=5$ GeV) allows one to reproduce well the data on $ρ$ at lower energies without additional free parameters
The high energy elastic nucleon cross section is treated from the viewpoint of the basic principles of local field theory. The connection between the energy dependence of $σ_{tot}$ and the $ρ$ - ratio of the real to imaginary parts of the forward elastic scattering amplitude is examined in the framework of dispersion relations, derivative dispersion relations and crossing symmetry.
A behavior of imaginary and real parts of the high-energy elastic hadron scattering amplitude is examined in the diffraction region. It is shown that the interference between Coulomb and hadronic scattering at small momentum transfers and especially in the region of diffractive minimum can bring some information about the structure of the hadron spin-non-flip amplitude.
With relation to the RHIC spin program we research the polarization effects in elastic proton-proton scattering at small momentum transfer and in the diffraction dip region. The calculations take into account the Coulomb-hadron interference effects including the additional Coulomb-hadron phase. In particular we show the impact of the form of the hadron potential at large distances on the behavior of the hadron spin-flip amplitude at small angles. The $t$-dependence of the spin-flip amplitude of high energy hadron elastic scattering is analyzed under different assumptions on the hadron interaction.
The impact of the form of the hadron potential at large distances on the behaviour of the hadron spin-flip amplitude at small angles is examined. The $t$-dependence of the spin-flip amplitude of high energy hadron elastic scattering is analyzed under different assumptions on the hadron interaction. It is shown that the long tail of the non-Gaussian form of the hadron potential of the hadron interaction in the impact parameter representation leads to a large value of the slope of the spin-flip amplitude (without the kinematical factor $\sqrt{|t|}$) as compared with the slope of the spin-non-flip amplitude. This effect can explain the form of the differential cross section and the analyzing power at small transfer momenta. The methods for the definition of the spin-dependent part of the hadron scattering amplitude are presented. A possibility to investigate the structure of the hadron spin-flip amplitude from the accurate measure of the differential cross section and the spin correlation parameters is shown.
The determination of magnitudes of basic parameters of the high energy elastic scattering amplitude are examined at small momentum transfers with taking account of the Coulomb-hadron interference effects.
Several methods of extracting the magnitude of the real parts of the elastic hadron scattering amplitude - from the experimental data are presented. These methods allows us to obtain the real parts at one definite point of the transfer momentum and with a high accuracy without knowledge of the precise values of the normalization coefficient and with minimum theoretical assumptions.
The Coulomb-hadron interference effects are examined at small and large $t$. The methods for the definition of spin-dependent parts of hadron scattering amplitude are presented. The additional contributions to analyzing power $A_N$ and the double spin correlation parameter $A_{NN}$ owing to the electromagnetic-hadron interference are determined in the diffraction dip domain of high-energy elastic hadron scattering.
New methods have been developed for extracting the parameters of diffraction scattering amplitude, $σ_{tot}$ and $ρ=Re F_N/Im F_N$, from experimental data. The latter determines these parameters with less errors and without the knowledge of the normalization coefficient. The impact of additional information from the measurement of the spin-dependence cross section on the determination of the basic characteristic of elastic scattering amplitude is examined. The new form of the connection between some characteristics of the analyzing power and magnitude of the $pp-$ total cross section is presented.
Spin-dependent pomeron effects are analyzed for elastic $pp$ scattering and calculations for spin-dependent differential cross sections, analyzing power and double-spin correlation parameters are carried out for the energy range of the Relativistic Heavy Ion Collider (RHIC) at BNL. In this energy range, $50 \leq \sqrt{s} \leq 500 \gev$, the structure of pomeron-proton coupling can be measured at RHIC with colliding polarized proton beams.
Predictions of the elastic proton-proton cross sections at energies of LHC are calculate on the base of the high energy dynamical model. The growth of $ds/dt$ at fixed transfer momenta are shown. The form of eikonal of elastic hadron scattering at super high energies is discussed.
The spin correlation parameters, polarization - $A_{N}$ and double spin correlation parameters - $A_{NN}$, are calculated in the framework of dynamical model (GKS) of the hadron-hadron interection in the whole region of small angles and for energy HERA-N $\sqrt{s}=40 GeV$. It is shown that the measurements of such spin effects at small trunsfer momenta, in the region of the dip structure and at $t=-4 GeV^{2}$ have to give significant values of such spin correlation parameters.
The intercept of the supercritical Pomeron is examined with the use of different forms of the scattering amplitudes of the bare Pomeron. The one-to-one correspondence between the eikonal phase and the ratio of the elastic and total cross section is shown. Based on new experimental data of the CDF Collaboration, the intercept and power of the logarithmic growth of the bare and total Pomeron amplitude are analyzed. It is shown that as a result of the eikonalization procedure, the bare QCD Pomeron becomes compatible with experiment.