Sum rules for spin asymmetries
Starting from rotational invariance we derive sum rules for the single-spin asymmetries in inclusive production and binary processes. We also get sum rules for spin correlation parameters in elastic pp-scattering.
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Publications and source records attributed to S. M. Troshin.
Starting from rotational invariance we derive sum rules for the single-spin asymmetries in inclusive production and binary processes. We also get sum rules for spin correlation parameters in elastic pp-scattering.
We asses a role of the double helicity-flip amplitudes in small-angle elastic pp-scattering and obtain a new unitary bound for the double helicity-flip amplitude F_2 in elastic pp-scattering at small values of t on the basis of the U-matrix method of the s-channel unitarization.
The universality of single-spin asymmetry on inclusive pi-meson production is discussed. This universality can be related to the hadron substructure - constituent quarks.
The nonperturbative mechanism for spin effects in inclusive production based on the constituent quark model is considered. The main role belongs to the orbital angular momentum and the polarization of the $\bar q q$--pairs in the internal structure of the constituent quarks.
We note that recent results on the role of final state interactions in deep inelastic scattering make more complicated an extraction of a nucleon spin fraction carried by quarks from the experimental data obtained in deep inelastic scattering.
Phenomena related to the non-perturbative aspects of strong interactions at the LHC are discussed with emphasis on elastic and inelastic soft and hard diffraction processes. Predictions for the global characteristics and angular distributions in proton-proton collisions with elastic and multiparticle final states are given. Potential for discovery of the novel effects related to the increasing role of the elastic scattering at the LHC energies and its physical implications in diffractive and multiparticle production processes are reviewed.
It is shown that the universality of the initial and final state interactions responsible for the transition between the on-- and off--mass shell states leads to the energy independence of the ratio of exclusive $ρ$ electroproduction cross section to the total cross section. It is demonstrated that the above universality and explicit mass dependence of the exponent in the power--like energy behavior of the cross-section obtained in the approach based on unitarity is in a quantitative agreement with the high--energy HERA experimental data. We discuss also HERA results on angular distributions of vector--meson production.
We discuss recent HERA results on vector--meson electroproduction gamma*p -> Vp and demonstrate that universality of the initial and final state interactions responsible for the transition between the on- and off-mass shell states allows to explain energy independence of the ratio of exclusive rho electroproduction cross section to the total cross section. We also predict explicit mass dependence of this ratio for other vector mesons.
We discuss the role of absorbtion and antishadowing in particle production. We reproduce power-like energy behavior of the mean multiplicity in the model with antishadowing and discuss physical implications of such behavior for the hadron structure.
We discuss role of absorbtion and antishadowing in particle production. Antishadowing, which leads to domination of elastic scattering at high energies, appears to be consistent with growth of mean multiplicity in hadronic collisions. Moreover, we demonstrate possibility to reproduce power-like energy behavior of the mean multiplicity in the model with antishadowing and discuss physical implications of such behavior for the hadron structure.
We provide a brief topical outline of the persisting problem of the hyperon polarization and consider some future experimental prospects. The predictions which deserve experimental verification are proposed.
We demonstrate that the explicit mass dependence of the exponent in the power--like energy behavior of the vector--meson production cross-section in the processes of virtual photon interactions with a proton gamma^*p --> Vp obtained in the off--shell extension of the approach based on unitarity is in a quantitative agreement with the high--energy HERA experimental data.
Unitarity and geometrical effects are discussed for photon--photon scattering.
Deep-inelastic scattering at low Bjorken x and elastic vector meson electroproduction are analyzed on the basis of the off-shell s-channel unitarity. We discuss behavior of the total cross-section of virtual photon-proton scattering and obtain, in particular, that the exponent in the power-like dependence of $σ^{tot}_{γ^* p}$ is related to the interaction radius of a constituent quark. The explicit mass dependence of the exponent in the power energy behavior of the vector meson electroproduction has been obtained. Angular distributions at large momentum transfers are considered. The energy dependence of the total cross-section of $γ^*γ^*$-interactions is also obtained.
Interest and problems in the studies of diffraction at LHC are highlighted. Predictions for the global characteristics of proton-proton interactions at the LHC energy are given. Potential discoveries of the antishadow scattering mode and diffractive scattering conjugated with high--$E_T$ jets are discussed.
Deep-inelastic scattering at low x and elastic vector meson production are considered on the basis of the off-shell extension of the s-channel unitarity. We discuss behavior of the structure function F_2(x,Q^2) at low x and the total cross-section of virtual photon-proton scattering and obtain, in particular, the dependence sigma^{tot}_{gamma^* p}\sim (W^2)^{lambda(Q^2)} where exponent lambda(Q^2) is related to the interaction radius of a constituent quark. The energy dependence of the total cross-section of gamma^*gamma^*-interactions is calculated. The explicit mass dependence of the exponent in the power energy behavior of the vector meson production in the processes of virtual photon interactions with a proton gamma^*p to Vp has been obtained. We also consider angular distributions at large momentum transfers.
We consider angular dependence of the diffractive dissociation processes at high energies. It appeared that angular dependence of the diffractive dissociation has no dip and bump structure at the LHC energies and would show a smooth power-like decrease with $t$. The normalized differential cross-section has a scaling behavior and depends on the ratio $-t/M^2$ only. These results reflect general trends of unitarity limitations at high energies and are realized within the chiral quark model with unitarization performed through the generalized reaction matrix.
On the grounds of extension of the U-matrix unitarization to the off-shell scattering we consider virtual-photon induced scattering. We discuss behavior of the structure function F_2(x,Q^2) at low x and the total cross-section of virtual-photon proton scattering and obtain, in particular, the dependence sigma^{tot}_{gamma^*p}\sim(W^2)^{lambda(Q^2)}, where exponent lambda(Q^2) is related to the interaction radius of a virtual constituent quark.