arXiv subjects

A. I. Fix

Publications and source records attributed to A. I. Fix.

4 recordsLinked to original sources

arXiv2026

Tensor analyzing power $T_{20}$ in the reaction $\gamma \vec{d}\to pn$ at photon energies 350-680 MeV

We present measurements of the tensor analyzing power $T_{20}$ in the reaction $\gamma {d}\to pn$ at photon energies $E_\gamma = 350$-$680$~MeV. The experiment was performed at the VEPP-3 storage ring using an internal tensor-polarized deuterium gas target and a tagged quasi-real photon beam. The data were obtained for proton emission angles $\Theta_p = 70^\circ$-$102^\circ$. Comparison with modern meson-baryon calculations shows generally satisfactory agreement within the present uncertainties. A theoretical analysis of an extended data set, covering the energy range from threshold to 680~MeV and including both the new data and the previous results from 2007, is presented.

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arXiv2006

Binding of charmonium with two- and three-body nuclei

The energies of the (eta_c d) and (eta_c 3He) bound states are calculated on the basis of exact three- and four-body AGS equations. For the eta_c N interaction a Yukawa-type potential has been adopted. The calculations are done for a certain range of its strength parameter. The results obtained are quite different from calculations based on the folding model.

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arXiv2002

Search for Delta^++ component in 12^C ground state using 12^C(gamma, pi^+ p) reaction

The differential cross section for the $^{12}$C$(γ,π^{+}p)$ reaction has been measured in the $Δ$(1232) resonance region at high recoil momenta of the residual nuclear system. The data are analyzed under the assumption that the formation of the $π^+p$ pairs may be interpreted as a $γΔ^{++}\toπ^+p$ process which takes place on a $Δ^{++}$ preexisting in the target nucleus. Estimates of the $Δ^{++}$ momentum distribution $ρ_{Δ^{++}}(\bar{p})$=0.17 fm$^3$ for a mean momentum $\bar{p}=300\pm49$ MeV/c as well as the number of $Δ$ isobars per nucleon $N_Δ=0.017$ were obtained for $^{12}$C.

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arXiv1999

Search for the $Δ^{++}$ component in $^{12}C$ ground state using $^{12}C(γ, π^{+}p)$ reaction

The differential cross section for the reaction $^{12}$C$(γ,π^{+}p)$ has been measured in the $Δ$ resonance region at high recoil momenta of the residual nuclear system. The data are analysed under the assumption that the formation of $π^+p$ pairs may be interpreted as $γΔ^{++}\toπ^+p$ process, proceeding on the $Δ^{++}$ constituent in a target nucleus. As a result, the estimation $N_Δ=0.028\pm 0.008$ deltas per nucleon in $^{12}$C was obtained.

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