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V. V. Anisovich

Publications and source records attributed to V. V. Anisovich.

At least 19 recordsLinked to original sources
arXiv2020

New narrow LHCb pentaquarks as lowest antiquark-diquark-diquark systems

The antiquark-diquark-diquark model describes pentaquark states both in terms of quarks and hadrons. We discuss pentaquark states with hidden charm $P(\bar c cuud)$ discovered in the $J/Ψp$ spectrum by the LHCb collaboration. We consider three pentaquark states as members of the lowest ($S$-wave) multiplet and discuss the mass splitting scheme. The latest LHCb data for pentaquarks with hidden charm provide an opportunity to make an assumption about the diquark content of the pentaquark states. We give a classification for the LHCb pentaquarks and define recombination channels for these states.

hep-ph↗
arXiv2017

Diquark-diquark-antiquark model for pentaquarks with hidden charm: current status and problems

The $J/ψp$ signals at 4380 MeV and 4450 MeV which were seen by the LHCb collaboration in the decay $Λ^0_b\to K^-J/ψp$ are discussed following the hypothesis of the existence of diquark-diquark-antiquark composite states. The discussed problems concern: (i) estimation of masses and mass splittings for low-lying states, (ii) determination of decay modes in the quark recombination scheme, (iii) unitarity and analyticity constrains for pentaquark propagators, (iv) hadronic deuteron-like components in the diquark-diquark-antiquark multiplet.

hep-ph↗
arXiv2017

Narrow pentaquarks as diquark-diquark-antiquark systems

The diquark-diquark-antiquark model describes pentaquark states both in terms of quarks and hadrons. The latest LHCb data for pentaquarks with open charm emphasize the importance of hadron components in the structure of pentaquarks. We discuss pentaquark states with hidden charm $P(\bar c cuud)$ and those with open charm $P(\bar uussc)$ which were discovered recently in LHCb data ($J/Ψp$ and $Ξ_c^+ K^-$ spectra correspondingly). Considering the observed states as members of the lowest (s-wave) multiplet we discuss the mass splitting of states and the dumping of their widths.

hep-ph↗
arXiv2016

Propagators of resonances and rescatterings of the decay products

Hadronic resonance propagators which take into account the analytical properties of decay processes are built in terms of the dispersion relation technique. Such propagators can describe multi-component systems, for example, those when quark degrees of freedom create a resonance state, and decay products correct the corresponding pole by adding hadronic deuteron-like components. Meson and baryon states are considered, examples of particles with different spins are presented.

hep-ph↗
arXiv2016

Asymptotic regimes for hadron diffractive scatterings and coulomb interaction. Arguments for the black disk mode

Comparative analysis of the interplay of hadron and Coulomb interactions in $pp^\pm$ scattering amplitudes is performed in a broad energy interval, $\sqrt{s}=1-10^6$ TeV, for two extreme cases: for the asymptotic interactions of hadrons in black disk and resonant disk modes. The interactions are discussed in terms of the $K$-matrix function technique. In the asymptotic regime the real part of the hadronic amplitude is concentrated in both cases on the boundary of the disks in the impact parameter space but the LHC energy region is not asymptotic for the resonant disk mode that lead to a specific interplay of hadronic and coulombic amplitudes. For the $pp$ scattering at $\sqrt{s}\sim 10$ TeV an interplay of the hadron and Coulomb interactions in the resonant disk modes is realized in a shoulder in $dσ_{el}/d{\bf q}^2$ at ${\bf q}^2\sim 0.0025-0.0075$ GeV$^2$. The absence of such a shoulder in the data at 8 TeV can be considered as an argument against the resonant disk mode.

hep-ph↗
arXiv2016

Hadron diffractive scattering at ultrahigh energies and coulomb interaction

We study the interplay of hadronic and Coulomb interactions for $pp$ scattering at LHC energies on the basis of the previous determination of the real part of the amplitude [{\it V.V. Anisovich, V.A. Nikonov, J. Nyiri}, Int. J. Mod. Phys. A{\bf 30}, 1550188 (2015)]. The interference of hadron and Coulomb interactions is discussed in terms of the $K$-matrix function technique. Supposing the black disk mode for the asymptotic interaction of hadrons, we calculate interference effects for the energies right up to $\sqrt{s}= 10^6$ TeV. It turns out that the real part of the amplitude is concentrated in the impact parameter space at the border of the black disk that results in a growth of interplay effects with the energy increase.

hep-ph↗
arXiv2015

Hadron diffractive scattering at ultrahigh energies, real part of the amplitude and Coulomb interaction

On the basis of requirements of unitarity and analyticity we analyze the real and imaginary parts of the $pp^\pm$ scattering amplitudes at recent ultrahigh energies, 1-100 TeV. The predictions for the region $\sqrt s > 100$ TeV and ${\bf q}^2<0.4$ GeV$^2$ are given supposing the black disk asymptotic regime. It turns out that the real part of the amplitude is concentrated in the impact parameter space at the border of the black disk. The interplay of hadron and Coulomb interactions is discussed in terms of the $K$-matrix function. The $pp$ diffractive scattering cross section at 7 TeV is calculated with Coulomb interaction taken into account.

hep-ph↗
arXiv2015

Pentaquarks and strange tetraquark mesons

We consider the interplay of the pentaquark states and strange tetraquark states in the decay $Λ^0_b\to K^-J/ψp$. Possible existence of ($cs\bar c\bar u$)-states is taken up and their manifestation in the $K^-J/ψ$-channel is discussed. It is emphasised that these exotic mesons can imitate broad bumps in the in the $pJ/ψ$-channel.

hep-ph↗
arXiv2015

Pentaquarks and resonances in the $pJ/ψ$ spectrum

We consider exotic baryons with hidden charm as antiquark-diquark-diquark composite systems. Spin and isospin structure of such exotic states is given and masses are estimated. The data for production of pentaquarks in the reaction $Λ_b\to K^-p J/ψ$ are discussed. We suggest that the narrow peak in $pJ/ψ$ spectra at 4450 MeV is antiquark-diquark-diquark state with negative parity, $5/2^{-}(4450)$, while the broad bump $3/2^{+}(4380)$ is the result of rescatterings in the ($pJ/ψ$)-channel. Positions of other pentaquarks with negative parity are estimated.

hep-ph↗
arXiv2015

Exotic mesons with hidden charm as diquark-antidiquark states

Exotic mesons with hidden strange ($s\bar s$) and heavy quark pairs ($Q\bar Q$), where $Q=c,b$, are considered as diquark-antidiquark systems, $(Qs)(\bar Q\bar s)$. Taking into account that these states can recombinate into two-meson ones, we study the interplay of these states in terms of the dispersion relation D-function technique. The classification of exotic mesons is discussed, coefficients for decay modes are given, predictions for new states are presented. The nonet structure for $((Qq)(\bar Q \bar q)$, ($(Qs)(\bar Q\bar s$)), ($(Qq)(\bar Q\bar s))$- states ($q=u,d$) is suggested.

hep-ph↗
arXiv2014

Central production of lepton-antilepton pairs and heavy quark composite states in hadron diffractive collisions at ultrahigh energies

Central production of lepton-lepton pairs ($e^+e^-$ and $μ^+μ^-$) and heavy quark composite states (charmonia and bottomonia) in diffractive proton collisions (proton momenta transferred ${|\bf q_\perp}|\sim m/\ln s$) are studied at ultrahigh energies ($\ln{s}>>1$), where $σ_{tot}(pp^\pm)\sim\ln^N s$ with $1\la N\la 2$. The $pp^\pm$-rescattering corrections, which are not small, are calculated in terms of the $K$-matrix approach modified for ultrahigh energies. Two versions of hadron interactions are considered in detail: the growth (i) $σ_{tot}(pp^\pm)\sim\ln^2 s$, $σ_{inel}(pp^\pm)\sim\ln^2 s$ within the black disk mode and (ii) $σ_{tot}(pp^\pm)\sim\ln^2 s$, $σ_{inel}(pp^\pm)\sim\ln s$ within the resonant disk mode. The energy behavior of the diffractive production processes differs strongly for these modes, thus giving a possibility to distinguish between the versions of the ultrahigh energy interactions.

hep-ph↗
arXiv2014

Hadron collisions at ultrahigh energies: black disk or resonant disk modes?

The analysis of current ultrahigh energy data for hadronic total cross sections and diffractive scattering cross sections points to a steady growth of the optical density with energy for elastic scattering amplitudes in the impact parameter space, $b$. At LHC energy the profile function of the $pp$-scattering amplitude, $T(b)$, reaches the black disk limit at small $b$. Two scenarios are possible at larger energies, $\sqrt{s}\ga 100$ TeV. First, the profile function gets frozen in the black disk limit, $T(b)\simeq 1$ while the radius of the black disk $R_{black\;disk}$ is increasing with $\sqrt s$, providing $σ_{tot}\sim \ln^2s$, $σ_{el}\sim \ln^2s$, $σ_{inel}\sim \ln^2s$. In another scenario the profile function continues to grow at $\sqrt{s}\ga 100$ TeV approaching the maximal value, $T(b)\simeq 2$, that means the resonant disk mode. We discuss features of the resonant disk mode when the disk radius, $R_{resonant\;disk}\,$, increases providing the growth of the total and elastic cross sections $σ_{tot}\sim \ln^2s$, $σ_{el}\sim \ln^2s$, but a more slow increase of inelastic cross section, $σ_{inel}\sim \ln s$.

hep-ph↗
arXiv2014

Hadron diffractive production at ultrahigh energies

Diffractive production is considered in the ultrahigh energy region where pomeron exchange amplitudes are transformed into black disk ones due to rescattering corrections. The corresponding corrections in hadron reactions $h_1+h_3\to h_1+h_2+h_3$ with small momenta transferred ($q^2_{1\to 1}\sim m^2/\ln^2s$, $q^2_{3\to 3}\sim m^2/\ln^2s$) are calculated in terms of the $K$-matrix technique modified for ultrahigh energies. Small values of the momenta transferred are crucial for introducing equations for amplitudes. The three-body equation for hadron diffractive production reaction $h_1+h_3\to h_1+h_2+h_3$ is written and solved precisely in the eikonal approach. In the black disk regime final state scattering processes do not change the shapes of amplitudes principally but dump amplitudes in a factor $\sim\frac 14$.

hep-ph↗
arXiv2014

Proton-proton, pion-proton and pion-pion diffractive collisions at ultra-high energies

The LHC energies are those at which the asymptotic regime in hadron-hadron diffractive collisions ($pp,πp,ππ$) might be switched on. Based on results of the Dakhno-Nikonov eikonal model which is a generalization of the Good-Walker eikonal approach for a continuous set of channels, we present a picture for transformation of the constituent quark mode to the black disk one. In the black disk mode ($\sqrt s \geq 10$ TeV) we have a growth of the logarithm squared type for total and elastic cross sections, $σ_{tot}\sim\ln^2s$ and $σ_{el}\sim\ln^2s$, and $(τ={\bf q}_\perp^2σ_{tot})$-scaling for diffractive scattering and diffractive dissociation of hadrons. The diffractive dissociation cross section grows as $σ_{D}\sim\ln{s}$, $σ_{DD}\sim\ln{s}$, and their relative contribution tends to zero: $σ_{D}/σ_{tot}\to 0$, $σ_{DD}/σ_{tot}\to 0$. Asymptotic characteristics of diffractive and total cross sections are universal, and this results in the asymptotical equality of cross sections for all types of hadrons (the Gribov's universality). The energy scale for switching on the asymptotic mode is estimated for different processes.

hep-ph↗
arXiv2013

Asymptotic regime for hadron-hadron diffractive collisions at ultrahigh energies

Using the pre-LHC and LHC data for $πp$ and $pp$ diffractive collisions we study the ultrahigh energy asymptotic regime in the framework of the black disk picture. The black disk picture, being constrained by the s-channel unitarity condition and the $t$-channel analyticity, gives rather definite predictions for diffractive processes increasing with the energy. To deal with the data, we consider the Dakhno-Nikonov eikonal model which predicts a growth of the $\ln^2s$ type for total and elastic cross sections and $(τ={\bf q}_\perp^2\ln^2s)$-scaling for diffractive scattering and diffractive dissociation of hadrons. According to the calculations, ultrahigh energy asymptotic characteristics of diffractive and total cross sections are universal, and this results in the asymptotic equality of cross sections for all types of hadrons. We estimate the energy scale of the asymptotics in different processes. The manifestation of the asymptotic regime in hadron fragmentation reactions is discussed.

hep-ph↗
arXiv2013

Proton-proton diffractive collisions at ultra-high energies

Proton-proton total and elastic cross sections are considered in the Dakhno-Nikonov eikonal model [L.G. Dakhno, V.A. Nikonov, Eur. Phys. J. A8, 209 (1999)] at ultra-high energies. The model takes into account the quark structure of hadrons and the gluon structure of the supercritical pomeron that results in colour screening. The pomeron is considered as an input interaction term. The model gives a reasonably good description of the preLHC and LHC data for $pp$ collisions with a growth of the type $\ln^2s$ for total and elastic cross sections and $(τ={\bf q}_\perp^2\ln^2s)$-scaling for diffractive scattering. We present parameters of the supercritical pomeron and provide predictions for the energy region $\sqrt{s}\sim 10^2-10^4$ TeV.

hep-ph↗