E. A. Strokovsky

A Study of the Proton Momentum Spectrum From Deuteron Fragmentation at 8.9 GeV/

Abstract The momentum spectrum of protons emitted at small angles in the stripping reaction d + 12 C → p + X has been measured at a deuteron momentum of 8.9 GeV/ c . The data are described in the framework of the Glauber-Sitenko theory using the hybrid model of the deuteron wave function which includes a six-quark state. The parameters of this state are determined. A shoulder in the spectrum has been observed in the proton momenta region which kinematically corresponds to the production of a dibaryon resonance with a mass from 2.0 to 2.2 GeV.

c

A search forKpp bound state (the lightest kaonic nucleus) has been performe d using theγd → KπX reaction at Eγ=1.5-2.4 GeV at LEPS / Pring-8. The di fferential cross section of Kπ photo-production o ff deuterium has been measured for the first time in this energy region, and a bump st ructure was searched for in the inclusive missing mass spectrum. A statistically significant bump structure was no t observed in the region from 2.22 to 2.36 GeV /c2, and the upper limits of the di fferential cross section for the Kpp bound state production were determined to be 0.1 − 7μ b (95% confidence level) for a set of assumed binding energy and width values.

and an Estimate of Admixture Parameters for the Six Quark State in Deuteron

Abstract The polarization transfer coefficient of the 12 C( d, p ) X reaction has been measured using a deuteron beam of the JINR synchrophasotron and the spectrometer ALPHA. The covered internal momentum range of the deuteron wave function is 0–0.51 GeV/c. The measured values compared with the ones obtained at lower energies at Saclay in term of internal momentum demonstrate the absence of essential energy and A-dependence of this observable. A comparison of the new polarization transfer data with earlier measurements of T20 demonstrates the existence of a systematic deviation from the Impulse Approximation independently of the kind of the deuteron wave function with S- and D-wave only.

Search for

The 0° differential cross sections of the12C(4He,p) and12C(4He,t) reactions have been measured at beam momenta of 4.52 and 2.69 GeV/c/nucleon, respectively. The proton and triton momentum distributions in4He are extracted from the cross sections using a relativistic impulse approximation. Some theoretical models based on realisticN-N potentials are examined for our data.

K^-pp

The (3He, t) charge-exchange reaction on carbon nuclei and protons, accompanied by the excitation of Δ isobars in a target, has been studied at beam momenta from 4.40 to 18.3 GeV/c. The analysis is performed to explain why the Δ-peak in the inclusive A(3He, t) and A(p, n) measurements is shifted towards lower energy transfers (in comparison with the reactions on free nucleons) but in the exclusive ones it is shifted towards higher transfers. An attempt is undertaken to determine the characteristics of Δ excitation in nuclei by a (3He, t) reaction that is free of the admixture of quasifree Δ production.

bound state via

A search forKpp bound state (the lightest kaonic nucleus) has been performe d using theγd → KπX reaction at Eγ=1.5-2.4 GeV at LEPS / Pring-8. The di fferential cross section of Kπ photo-production o ff deuterium has been measured for the first time in this energy region, and a bump st ructure was searched for in the inclusive missing mass spectrum. A statistically significant bump structure was no t observed in the region from 2.22 to 2.36 GeV /c2, and the upper limits of the di fferential cross section for the Kpp bound state production were determined to be 0.1 − 7μ b (95% confidence level) for a set of assumed binding energy and width values.

\gamma d \rightarrow K^+ \pi^-X

We measured diffractive scattering cross sections of alpha-particles on carbon, aluminium, copper and lead using the beam of the Dubna synchrophasotron at 3.64 GeV/nucleon. The data are compared with model predictions of the Glauber-Sitenko multiple scattering theory. Large discrepancies between experiment and calculations appear at four-momentum transfers above ∼0.25 (GeV/c)2. Various theoretical attempts to improve the description of high-energy alpha-scattering data are discussed.

reaction at

A search forKpp bound state (the lightest kaonic nucleus) has been performe d using theγd → KπX reaction at Eγ=1.5-2.4 GeV at LEPS / Pring-8. The di fferential cross section of Kπ photo-production o ff deuterium has been measured for the first time in this energy region, and a bump st ructure was searched for in the inclusive missing mass spectrum. A statistically significant bump structure was no t observed in the region from 2.22 to 2.36 GeV /c2, and the upper limits of the di fferential cross section for the Kpp bound state production were determined to be 0.1 − 7μ b (95% confidence level) for a set of assumed binding energy and width values.