arXiv subjects
Publications and source records attributed to A. G. Shuvaev.
The relation between four-dimensional $SO(4)$ pure Yang-Mills theory and the gravity is discussed. The functional integral for Yang-Mills theory is rewritten in terms of the gravity metric and Riemann tensors. This relation is shown to also provide a simple way to derive the linear potential resulting from the average Wilson loop in pure Yang-Mills theory.
The straightforward calculations of the reaction and interaction cross sections of the nuclear scattering are carried out in Glauber approach using the generating function method. It allows for the resummation of all orders of Glauber theory. The results are obtained for $^4$He, $^{11}$Li, $^{12}$C scattering on $^{12}$C target. The difference between the reaction and the differential cross section is shown to be not exceeding several percents
The differential elastic cross sections of $^{12}$C - $^{12}$C, $^{16}$O - $^{16}$O and $^{20}$Ne - $^{20}$Ne nuclei scattering are calculated in the complete Glauber theory with the account of the modification due to Coulomb interaction and form factor effects. The role of the Coulomb interaction is shown to be significant mainly in the diffractive minima. The results of the complete Coulomb calculations are noticeably different from those obtained in the Born approximation.
The complete Glauber calculation of the differential cross sections of $^{12}$C--$^{12}$C and halo nuclei on $^{12}$C scattering was performed using the previously proposed in Refs.~\cite{Shabelski:2021iqk, Shabelski:2022xkw} method of generating function. The results are different as compared with the similar calculations in the optical model and the rigid target approximation. The halo nuclei radii extracted from the scattering data via the complete Glauber analysis come out to be larger than those obtained in the approximate approaches
A new approach to deal with the scattering amplitudes in Glauber theory is proposed. It relies on the use of generating function, that has been explicitly found. The method is applied to the analytical calculation of the nucleus-nucleus elastic scattering amplitudes in the all interaction orders of the Glauber theory.
The differential elastic cross sections of $^{12}$C -- $^{12}$C and $^{11}$Li -- $^{12}$C nuclei are calculated in the complete Glauber theory. The role of the possible correlations connected to the shell effects in $^{11}$Li nucleus is considered.
The multiplicity distribution of the gluons produced at the high energy is evaluated in BFKL approach. The distribution has Poisson form that can explain experimentally observed KNO scaling.
We present the unified description of the existing data on elastic small angle $pp$ and $p \bar p$ scattering at the energies 1.8, 1.96, 2.76, 7, 8 and 13~TeV in the framework of Additive Quark Model. The agreement with the data is quite reasonable.
We consider the central exclusive production of high $E_T$ jets $pp\to p+(X+{\rm dijet})+p$. In particular we study the possible contamination of the purely exclusive signal by semi-exclusive production where no other secondaries are emitted in one hemisphere, between the highest $E_T$ dijet and the recoil proton, while in the other hemisphere a third jet, plus possibly additional hadron activity, is allowed, but still separated from the incoming proton by a large rapidity gap. This process arising from the fusion of a hard and a soft Pomeron has not been considered before. It turns out that it gives a negligible contribution. %contamination, which was not known before the calculation. The calculation involves a careful treatment of the QCD colour structure of the amplitudes.
Peripheral nucleon-nucleus collisions occur at the high energies mainly through the interaction with one constituent quark from the incident nucleon. The central collisions should involve all three constituent quarks and each of them can interact several times. We calculate the average number of quark-nucleus interactions for both the cases in good agreement with the experimental data on $ϕ$-meson, $K^{*0}$ and all charged secondaries productions in $p+Pb$ collisions at LHC energy $\sqrt s = 5$ TeV.
Elastic $pp$ scattering at LHC energies is treated in Additive Quark Model together with Pomeron exchange theory. The obtained results are compared with the new experimental data on the ratio of real to imaginary part of the scattering amplitude at the small transverse momenta
A new version of the $k_T$ factorization approach is formulated for the high energy heavy quark production. The results are in reasonable agreement with the experimental data at LHC energies.
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.
The large mass of the $η'$ meson indicates that a sizeable gluon component is present in the meson wave function. However, the $χ_{c0}$ and $χ_{c2}$ decays to $η'$ mesons, which proceed via a purely gluonic intermediate state and we would therefore naïvely expect to be enhanced by such a component, are in fact relatively suppressed. We argue that this apparent contradiction may be resolved by a proper treatment of interference effects in the decay. In particular, by accounting for the destructive interference between the quark and gluon components of the $η'$ distribution function, in combination with a model for strange quark mass effects, we demonstrate that the observed $χ_{c(0,2)}\toη(')η(')$ branching ratios can be reproduced for a reasonable gluon component of the $η'$, $η$ mesons.
High energy (CERN SPS and LHC) inelastic $pp$ ($p\bar p$) scattering is treated in the framework of additive quark model together with Pomeron exchange theory. We extract the midrapidity inclusive density of the charged secondaries produced in a single quark-quark collision and investigate its energy dependence. Predictions for the $πp$ collisions are presented.
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.
We study the prompt production of the $χ_c(1^+)$ and $χ_b(1^+)$ mesons at high energies. Unlike $χ(0^+,2^+)$ production, $χ(1^+)$ mesons cannot be created at LO via the fusion of two on-mass-shell gluons, that is $gg\toχ_{c,b}(1^+)$ are not allowed. However, the available experimental data show that the cross sections for $χ_c(1^+)$ and $χ_c(2^+)$ are comparable. We therefore investigate four other $χ(1^+)$ production mechanisms: namely, (i) the standard NLO process $gg\toχ_{c,b}(1^+)+g$, (ii) via gluon virtuality, (iii) via gluon reggeization and, finally, (iv) the possibility to form $χ_{c,b}(1^+)$ by the fusion of three gluons, where one extra gluon comes from another parton cascade, as in the Double Parton Scattering processes.
High energy (CERN SPS and LHC) $pp$ ($p\bar p$) scattering is treated in the framework of Additive Quark Model together with Pomeron exchange theory. The reasonable agreement with experimental data is achieved both for the elastic scattering and for the diffractive dissociation with natural parameters for the strong matter distribution inside proton.