arXiv subjects

Yu. N. Uzikov

Publications and source records attributed to Yu. N. Uzikov.

At least 19 recordsLinked to original sources

arXiv2025

Search for dibaryon resonances in the reactions $dd\to ddππ$ and $pd \to pdππ$

The isoscalar dibaryon resonance $D_{03}(2380)$, discovered at WASA@COSY in the total cross section of the reaction $pn\to dπ^0π^0$ and in the elastic pn scattering in the energy range corresponding to the invariant mass of the pn system of 2380 MeV, can reveal itself in the $pd\to pdππ$ and $dd\to ddππ$ reactions at higher energies due to deuteron excitation in the $t$ channel. In this paper, the cross sections of these reactions are estimated based on the model of the reaction $pn\to dπ^0π^0$, proposed earlier by Platonova and Kukulin.

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arXiv2025

Relations between spin observables of the reactions $dd\to npd$ and $pd\to pd$ in impulse approximation

It is shown that the vector and tensor analyzing powers $A_y$, $A_{yy}$ and also double spin correlation coefficients $C_{y,y}$, $C_{y y,y}$ of the reaction $dd\to n+p+d$ in impulse approximation are linearly connected to corresponding observables of the $pd$- elastic scattering. Obtained relations are necessary for motivation of the polarization experiments for the first phase of the SPD NICA project and for analysis of expected data.

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arXiv2025

Time-reversal invariance violation effect in $\bm{dd}$ scattering

A formalism has been developed for calculating the signal of violation of $T$ invariance, provided that $P$ invariance is preserved during the scattering of tensor-polarized deuterons on vector-polarized ones based on the Glauber theory with the full consideration of spin dependence of $NN$ elastic scattering amplitudes and spin structure of colliding deuterons. The numerical calculations have been carried out in the range of laboratory proton energies $T_p=0.1$--$1.2$ GeV using the SAID database for spin amplitudes and in the energy region of the SPD NICA experiment corresponding to the invariant mass of the interacting nucleon pairs $\sqrt{s_{NN}}= 2.5$--$25$ GeV, using two phenomenological models of $pN$ elastic scattering. It is found that only one type of the $T$ non-invariant $P$-invariant $NN$ interaction gives a non-zero contribution to the signal in question, that is important for isolating an unknown constant of this interaction from the corresponding data.

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arXiv2024

Test of $T$-invariance in scattering of polarized protons on tensor-polarized deuterons at energies of the NICA SPD

The effect of violation of $T$-invariance, provided that $P$-parity is preserved, is given by the total cross section of the interaction of a vector-polarized particle with a tensor-polarized target. A formalism for calculating this effect developed previously and based on the spin-dependent Glauber theory of elastic $pd$ scattering is used here to calculate the effect under discussion in the range of collision energies corresponding to the invariant mass of the $pN$ system $\sqrt{s_{pN}}=5$--$30$ GeV. The spin-dependent amplitudes of elastic $pN$ scattering required for this calculation are taken from existing phenomenological models for $pN$ scattering in the energy region considered.

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arXiv2024

Translationally invariant shell model calculation of the quasielastic $(p,2p)$ process at intermediate relativistic energies

Relativistic beams of heavy ions interacting with various nuclear targets allow to study a broad range of problems starting from nuclear equation of state to the traditional nuclear structure. Some questions which were impossible to answer heretofore -- can be addressed nowadays by using inverse kinematics. These includes the structure of short-lived nuclei and the precision study of exclusive channels with production of residual nuclei in certain quantum states. Theoretical understanding such processes is so far based on factorization models which combine the single-step amplitude of the reaction on a bound nucleon or nuclear cluster with a certain wave function of its relative motion with respect to the residual nucleus. The nuclear structure information is encoded in the spectroscopic amplitude, calculable within nuclear many-body theories. In this work, we use for this purpose the translationally-invariant shell model with configuration mixing and demonstrate that it successfully reproduces the single-differential and integrated cross sections of the quasielastic proton knockout, $^{12}\mbox{C}(p,2p)^{11}\mbox{B}$, with outgoing $^{11}$B in the ground state and low-lying excited states measured at GSI at 400 MeV/nucleon.

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arXiv2024

Double spin correlations in the reaction dd->pnpn and in the pn-elastic scattering

An unexpectedly large double spin correlation with a sharp dependence on energy, found in elastic proton-proton scattering at large angles in the c.m.s. energy range $\sqrt{s_{pp}}= 3 ÷5.5$ GeV, may be associated with the formation of exotic eight-quark resonances at the thresholds of the strangeness and charm production. For a deeper understanding of the dynamics of this process it is important to measure double spin correlation in elastic $pn$ scattering in the same kinematics. The possibility of obtaining this data from the reaction $d d\to pnp$ with two polarized deuterons on NICA SPD is considered in this paper.

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arXiv2024

Coherent interactions of a fast proton with a short-range $NN$ correlation in the nucleus

Nuclear structure at short $NN$-distances is still poorly understood. In particular, the full quantum structure of the nucleus with a correlated $NN$-pair is a challenge to theory. So far, model descriptions have been limited to the average mean-field picture of the remaining nuclear system after removing the $NN$-pair. In the recent experiment of the BM@N Collaboration at JINR \cite{Patsyuk:2021fju}, the reactions $^{12}\mbox{C}(p,2pn_s)^{10}\mbox{B}$ and $^{12}\mbox{C}(p,2pp_s)^{10}\mbox{Be}$ induced by the hard elastic $pp$ scattering were studied. Here, $n_s$ or $p_s$ denote the undetected slow nucleon in the rest frame of $^{12}\mbox{C}$. In contrast to the previous experiments, the residual bound nucleus was also detected which requires a new level of theoretical understanding. In the present work, we apply the technique of fractional parentage coefficients of the translationally-invariant shell model (TISM) to calculate the spectroscopic amplitude of the system $NN-B$ where $B$ is the remaining nuclear system. The spectroscopic amplitude enters the full amplitude of a nuclear reaction. The relative $NN-B$ wave function is no longer a free parameter of the model but is uniquely related to the internal state of $B$. The interaction of the target proton with the $NN$-pair is considered in the impulse approximation. We also include the initial- and final state interactions of absorptive type as well as the single charge exchange processes. Our calculations are in a reasonable agreement with the BM@N data.

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arXiv2023

The effect of $T$-invariance violation in scattering of polarized $^3$He nuclei on tensor-polarized deuterons

In the interaction of a transversely polarized nuclear beam with a tensor-polarized deuteron target, a nonzero value of the component of the total cross section of the process corresponding to this combination of polarizations is an unambiguous signal of $T$-invariance violation while $P$-parity is preserved. The method developed earlier for calculating this component of the total cross section for $pd$ scattering based on the Glauber theory has been generalized by us to the case of $^3$He$d$ scattering, and its energy dependence in the range of beam energies 0.1--1 GeV/nucleon has been calculated. It is found that in $^3$He$d$ collisions, in contrast to $pd$ scattering, the contribution of only one type of $T$-violating nucleon-nucleon forces dominates, which is essential for extraction of the unknown constant of this interaction from the corresponding data.

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arXiv2021

Possible studies at the first stage of the NICA collider operation with polarized and unpolarized proton and deuteron beams

This paper contains suggestions for experiments with usage of the Spin Physics Detector (SPD) at the first stage of the SPD NICA Programme developing at JINR. Double polarized pp-, dd- and pd- collisions at c.m.s. NN energies of 3.4-10 GeV, which will be accessible at the initial stage of experiments, allow one to study spin dependence of the NN interaction, search for multiquark states at double strangeness, charm and beauty thresholds, study the short-range structure of the deuteron. Double polarized pd scattering offer a possibility to test the Standard Model through the search for T-invariance violation.

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arXiv2020

Spin observables of proton-deuteron elastic scattering at SPD NICA energies within the Glauber model and pN amplitudes

A systematic analysis of nucleon-nucleon scattering amplitudes is available up to a laboratory energy of $3$~GeV in case of the $pp$ system and up to $1.2$ GeV for $pn$. At higher energies there is only incomplete experimental information on $pp$ elastic scattering, whereas data for the $pn$ system are very scarce. We apply the spin-dependent Glauber theory to calculate spin observables of $pd$ elastic scattering at $3$-$50$ GeV/c using $pp$ amplitudes available in the literature and parametrized within the Regge formalism. The calculated vector $A_y^p$, $A_y^d$ and tensor $A_{xx}$, $A_{yy}$ analyzing powers and the spin-correlation coefficients $C_{y,y}$, $C_{x,x}$, $C_{yy,y}$, $C_{xx,y}$ can be measured at SPD NICA and, thus, will provide a test of the used $pN$ amplitudes.

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arXiv2016

Polarized proton-deuteron scattering as a test of time-reversal invariance

Scattering of protons with transversal polarization $p_y^p$ on deuterons with tensor polarization $P_{xz}$ provides a null-test signal for time-reversal (T) invariance violating but parity (P) conserving effects. We calculate the corresponding null-test observable at beam energies 100-1000 MeV within the spin-dependent Glauber theory considering T-violating P-conserving nucleon-nucleon interactions. The S-wave component of the deuteron wave function as well as the D-wave are taken into account and the latter is found to play an important role for the magnitude and the energy dependence of the observable in question. Specifically, with inclusion of the D wave the maximum of the obtained signal is shifted to higher beam energies, i.e. to 700-800 MeV.

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arXiv2016

Search for scaling onset in exclusive reactions with the lightest nuclei

The dimensional scaling of the differential cross sections of binary reactions $dσ/d t\sim s^{-(n-2)}$, where $n$ is given by constituent quark counting rules, was predicted for asymptotically high energies $\sqrt{s}\gg m_i$ and transferred momenta $-t\gg m_i^2$ at $t/s=const$ (here $s$ and $t$ are the Mandelstam variables and $m_i$ denotes a hadron mass), but manifested itself at surprisingly moderate energies of few GeV at large fixed cms angles $θ_{cm}\sim 90^\circ$. This behaviour is observed not only in reactions with free hadrons, but with the deuteron and $^3He$ too both for electromagnetic and pure hadronic interactions. One may suppose that observed scaling points out to effective restoration of near-conformal and, probably, chiral symmetry in these processes. A systematical experimental study of the scaling behaviour of the reactions with the deuteron, $^3H$, $^3He$, and $^4He$ nuclei is still absent. We consider a possibility to carry out this study in $dd$ collisions at the JINR Nuclotron.

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arXiv2015

Test of time-reversal symmetry in the proton-deuteron scattering

The integrated cross section $\widetildeσ$ for a special type of double polarized proton-deuteron scattering constitutes a null test forvtime-invariance violating but P-parity conserving effects. Using the Glauber theory for the $pd$ elastic scattering and different types of phenomenological T-odd P-even NN-interactions we show that the contribution of the lowest mass meson exchange, i.e. the $ρ$-meson, to the null-test signal $\widetildeσ$ vanishes. Variation of the cross section $\widetildeσ$ due to strong hadronic and Coulomb interaction is studied and its energy dependence is calculated in the GeV region.

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arXiv2015

Polarized deuteron charge-exchange reaction $dp->{pp}_sNπ$ in the Delta-isobar region

Mechanisms of the charge exchange reaction $dp\to \{pp\}_{\!s} Nπ$, where $\{pp\}_{\!s}$ is a two-proton system at low excitation energy, are studied at beam energies 1 -- 2 GeV and for invariant masses $M_X$ of the final $Nπ$ system that correspond to the formation of the $Δ(1232)$ isobar. The direct mechanism, where the initial proton is excited into the $Δ(1232)$, dominates and explains the existing data on the unpolarized differential cross section and spherical tensor analyzing power $T_{22}$ for $M_X> 1.2$ GeV/$c^2$. However, this model fails to describe $T_{20}.

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arXiv2013

Elastic pbar-d scattering and total pbar-d cross sections reexamined

We update our recent analysis of pbar-d scattering, performed within the Glauber theory including the single- and double pbar-N scattering mechanisms. Specifically, now we consider also Nbar-N amplitudes from a new partial-wave analysis of pbar-p scattering data. Predictions for differential cross sections and the spin observables A_y^d, A_y^pbar, A_xx, A_yy are presented for antiproton beam energies between 50 and 300 MeV. Total polarized cross sections are calculated utilizing the optical theorem. The efficiency of the polarization buildup for antiprotons in a storage ring is investigated.

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arXiv2013

Elastic pbar-d scattering and total pbar-d cross sections

Elastic pbar-d scattering is studied within the Glauber theory based on the single- and double pbar-N scattering mechanisms. The full spin dependence of the elementary pbar-N scattering amplitudes is taken into account and both the S- and D-wave components of the deuteron are considered. The treatment of the spin dependence is done in a (properly modified) formalism developed recently by Platonova and Kukulin for the pd -> pd scattering process. Predictions for differential cross sections and the spin observables A_y^d, A_y^pbar, A_xx, A_yy are presented for antiproton beam energies between 50 and 300 MeV, using amplitudes generated from the Nbar-N interaction model developed by the Juelich group. Total polarized cross sections are calculated utilizing the optical theorem. The efficiency of the polarization buildup for antiprotons in a storage ring is investigated.

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arXiv2012

Spin dependence of the pbar-d and pbar-3He interactions

Elastic scattering of antiprotons on deuteron and 3He targets is studied within the Glauber-Sitenko theory. In case of pbar-d scattering, the single- and double pbar-N scattering mechanisms and the full spin dependence of the elementary pbar-N scattering amplitudes are taken into account on the basis of an appropriately modified formalism developed for p-d scattering. Differential cross sections and analyzing powers are calculated for antiproton beam energies between 50 and 300 MeV, using the Nbar-N model of the Juelich group as input. Results for total polarized cross sections are obtained via the optical theorem. The efficiency of the polarization buildup for antiprotons in a storage ring is discussed.

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arXiv2011

Comparison of inclusive K+ production in proton-proton and proton-neutron collisions

The momentum spectra of K+ produced at small angles in proton-proton and proton-deuteron collisions have been measured at four beam energies, 1.826, 1.920, 2.020, and 2.650 GeV, using the ANKE spectrometer at COSY-Juelich. After making corrections for Fermi motion and shadowing, the data indicate that K+ production near threshold is stronger in pp- than in pn-induced reactions. However, most of this difference could be made up by the unobserved K0 production in the pn case.

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