Study of the Production of Positively Charged Pions in Proton–Proton Collisions in the Range of Primary Momenta between 1345 and 1536 MeV/ $$c$$

Physics of Atomic Nuclei - Differential cross sections obtained for the reaction $$ppto pnpi^{+}$$ at five incident proton momenta of 1345, 1393, 1439, 1486, and 1536 MeV/c are presented. The...     

The K0 SK0 S final state in two-photon collisions and SU(3) tensor nonets

The K⁰ _SK⁰ _S final state in two-photon collisions is studied with the L3 experiment at LEP, using orbital angular momentum operators. The mass spectrum is dominated by the formation of tensor mesons, their two-photon partial width are determined. A signal at 1700-1800MeV is found to be a new tensor state f ₂(1750) with mass M = (1755±10)MeV and width Γ = (67±12)MeV. All observed tensor resonances obey SU(3) relations. The f ₂(1750) state forms a second tensor nonet together with f ₂(1560) and a ₂(1700). The SU(3) analysis allows us to determine with good accuracy mixing angles between nonstrange and strange components of the isoscalar members of tensor nonets.     

Determination of hadronic partial widths for scalar-isoscalar resonances f0(980), f0(1300), f0(1500), f0(1750) and the broad state f0(1530 ?250+90 )

Recently [see V.V. Anisovich et al., Yad. Fiz. 63, 1489 (2000)], the K-matrix solutions for the wave IJ ^PC=00⁺⁺ were obtained in the mass region 450–1900 MeV, where four resonances f ₀(980), f ₀(1300), f ₀(1500), f ₀(1750) and the broad state f ₀(1530 ₋₂₅₀ ⁺⁹⁰ ) are located. Based on these solutions, partial widths are determined for scalar-isoscalar states decaying into the channels ππ, KK ηη, ηη′, ππππ and corresponding decay couplings. From Yadernaya Fizika, Vol. 65, No. 8, 2002, pp. 1583–1590. Original English Text Copyright ? 2002 by Anisovich, Nikonov, Sarantsev. This article was submitted by the authors in English.     

Quark-antiquark states and their radiative transitions in terms of the spectral integral equation: Charmonia

Earlier by the authors (Yad. Fiz. 70, 68 (2007)), the bƃ states were treated in the framework of the spectral integral equation, together with simultaneous calculations of radiative decays of the considered bottomonia. In the present paper, such a study is carried out for the charmonium states. We reconstruct the interaction in the c-c sector on the basis of the data for the charmonium levels with J _PC = 0⁻⁺, 1⁻⁻, 0⁺⁺, 1⁺⁺, 2⁺⁺, 1⁺⁻ and radiative transitions ψ(2S) → γχ _c0(1P), γχ _c1(1P), γχ _c2(1P), γχ _c(1S) and χ _c0(1P), χ _c1(1P), χ _c2(1P) → γJ/ψ. The c-c levels and their wave functions are calculated for the radial excitations with n ≤ 6. Also, we determine the c-c component of the photon wave function using the e ⁺ e ⁻-annihilation data: e ⁺ e ⁻ → J/ψ(3097), ψ(3686), ψ(3770), ψ(4040), ψ(4160), ψ(4415) and perform the calculations of the partial widths of the two-photon decays for the n = 1 states η _c0(1S), χ _c0(1P), χ _c2(1P) → γγ and n = 2 states η _c0(2S) → γγ, χ _c0(2P) → γγ. We discuss the status of the recently observed c-c states X(3872) and Y(3941): according to our results, the X(3872) can be either χ _c1(2P) or η _c2(1D), while Y(3941) is χ _c2(2P). The text was submitted by the authors in English.     

The study of the negative pion production in neutron-proton collisions at beam momenta below 1.8 GeV/c

A detailed investigation of the reaction np ? \rightarrow pp p^- \pi^{{-}}_{} has been carried out using the data obtained with the continuous neutron beam produced by charge exchange scattering of protons off the deuterium target. Partial-wave event-by-event analysis based on the maximum likelihood method was applied to determine contributions of different partial waves to the pion production process. A combined analysis of the np ? \rightarrow pp p^- \pi^{{-}}_{} and pp ? \rightarrow pp p⁰ \pi^{{0}}_{} data measured in the same energy region allows us to determine the contribution of isoscalar partial waves (I = 0 in the momentum range from 1.1 up to 1.8GeV/c . The decay of isoscalar partial waves into the (¹ S ₀)_pp p \pi channel provides us with a good tool for the determination of the pp S -wave scalar scattering length in the final state which was found to be a _pp = - 7.5±0.3 fm.     

Sensitivity of cross sections for elastic nucleus-nucleus scattering to halo nucleus density distributions

In order to clear up the sensitivity of the nucleus-nucleus scattering to the nuclear matter distributions in exotic halo nuclei, we have calculated differential cross sections for elastic scattering of the ⁶He and ¹¹Li nuclei on several nuclear targets at the energy of 0.8 GeV/nucleon with different assumed nuclear density distributions in ⁶He and ¹¹Li.     

The analysis of reactions π<Subscript>N</Subscript> → <Emphasis Type="Italic">two mesons</Emphasis> + <Emphasis Type="Italic">N</Emphasis> within reggeon exchanges. Fit and results

We present technical aspects of the fitting procedure given in the paper by V.V. Anisovich and A.V. Sarantsev “The analysis of reactions πN → two mesons + N within reggeon exchanges. Fit and results.”     

The analysis of reactions <Emphasis Type="Italic">πN</Emphasis> → <Emphasis Type="Italic">two mesons</Emphasis> + <Emphasis Type="Italic">N</Emphasis> within reggeon exchanges. Basic formulas for fit

We present technical aspects of the fitting procedure given in the paper by V.V. Anisovich and A.V. Sarantsev “The analysis of reactions πN → two mesons + N within reggeon exchanges. Fit and results.”