arXiv subjects

Yu. D. Prokoshkin

Publications and source records attributed to Yu. D. Prokoshkin.

4 recordsLinked to original sources

arXiv1997

Study of the $ηπ^o$ system in the mass range up to 1200 MeV

The reaction $π^-p \to ηπ^o n$ has been studied with GAMS-2000 spectrometer in the secondary 38 GeV/c $π^-$-beam of the IHEP U-70 accelerator. Partial wave analysis of the reaction has been performed in the $ηπ^o$ mass range up to 1200 MeV. The $a_0(980)$-meson is seen as a sharp peak in S-wave. The $t$-dependence of $a_0(980)$ production cross section has been studied. Dominant production of the $a_0(980)$ at a small transfer momentum $t$ confirms the hypothesis of Achasov and Shestakov about significant contribution of the $ρ_2$ exchange ($I^GJ^{PC}=1^+2^{--}$) in the mechanism of $a_0(980)$ meson production in $t$-channel of the reaction.

hep-ex↗

arXiv1997

The two-pion spectra for the reaction π^- p -> π^0π^0 n at 38 GeV/c pion momentum and combined analysis of the GAMS, Crystal Barrel and BNL data

We perform the K-matrix analysis of meson partial waves with IJ^{PC} =00^{++}, 10^{++}, 02^{++}, 12^{++} basing on GAMS data on π^-p -> π^0π^0 n, ηηn, ηη' n together with BNL data on π^-p -> K\bar K n and Crystal Barrel data on p\bar p (at rest) -> π^0π^0π^0, π^0ηη, π^0π^0η. The positions of the amplitude poles (physical resonances) are determined as well as the positions of the K-matrix poles (bare states) and the values of bare state couplings to two-meson channels. Nonet classification of the determined bare states is discussed.

hep-ph↗

arXiv1996

Nonet Classification of Scalar/Isoscalar Resonances in the Mass Region below 1900 MeV: Observation of the Lightest Scalar Glueball

We summarize the results of the investigation of the $IJ^{PC}=00^{++}$ wave which is devoted to the search for the lightest scalar glueball. In the framework of the K-matrix formalism, the $q\bar q$-nonet classification of the scalar/isoscalar states is performed in the mass region below 1900 MeV basing on the following data: GAMS data for $π^-p\toπ^0π^0n$, $ηηn$, $ηη'n$; CERN-Münich data for $π^-p\toπ^+π^-n$; Crystal Barrel data for $p\bar p\toπ^0π^0π^0$, $π^0π^0η$, $π^0ηη$; BNL data for $ππ\to K\overline K$. It is shown the existence of an extra state for $q\bar q$ classification: this state is a good candidate for the lightest scalar glueball. Analysis of the glueball/$q\bar q$ mixing shows that the glueball state has mainly dispersed over three real resonances: $f_0(1300)$, $f_0(1500)$ and $f_0(1530^{+90}_{-250})$. The broad resonance with complex mass $m=1530^{+90}_{-250}-i(560\pm 140)$ MeV is descendant of the pure glueball. The restored mass of the pure glueball is equal to 1695 MeV. This value agrees well with the results of lattice gluodynamics.

hep-ph↗

arXiv1996

Nonet Classification of Scalar/Isoscalar Resonances below 1900 MeV: the Existence of an Extra Scalar State in the Region 1200-1600 MeV

A classification of the $IJ^{PC}=00^{++}$ mesons is performed on the basis of the K-matrix analysis of meson spectra in the reactions: (i) GAMS data on $πp\to π^0π^0 n$, $ηηn$, $ηη' n$; (ii) Crystal Barrel data on $p\bar p~(at~rest)\to π^0π^0π^0$, $π^0π^0η$, $π^0ηη$; (iii) CERN-Münich data on $πp\to π^+π^- n$; (iiii) BNL data on $πN\to K\bar K N$. The analysis points to the existence of four comparatively narrow scalar resonances which correspond to the following poles of the scattering amplitude (in MeV): $(1015\pm 15)- i(43\pm 8)$, $(1300\pm 20)-i(120\pm 20)$, $(1499\pm 8)-i(65\pm 10)$ and $(1780\pm 30)-i(125\pm 70)$. The scattering amplitude also has a fifth pole $f_0(1530^{+90}_{-250})$ at the complex mass $(1530^{+90}_{-250}) - i(560\pm 140)$. The masses of the K-matrix poles (bare states) are at $720\pm 100$ MeV, $1230\pm 50$ MeV, $1260\pm 30$ MeV, $1600\pm 50$ MeV and $1810\pm 30$ MeV. The quark content of the bare states is analyzed using the values of their couplings to the $ππ$, $K\bar K$, $ηη$ and $ηη'$. It is shown that one of the bare states in the mass region 1200-1600 MeV is superfluous for the $q\bar q$ classification and should be considered as the lightest glueball.

hep-ph↗