89 research outputs found

    Exclusive Measurements of pp -> dpi+pi0: Double-Pionic Fusion without ABC Effect

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    Exclusive measurements of the reaction pp -> dpi+pi0 have been carried out at T_p = 1.1 GeV at the CELSIUS storage ring using the WASA detector. The isovector pi+pi0 channel exhibits no enhancement at low invariant pipi masses, i. e. no ABC effect. The differential distributions are in agreement with the conventional t-channel Delta-Delta excitation process, which also accounts for the observed energy dependence of the total cross section. This is an update of a previously published version -- see important note at the end of the article

    To the 50th anniversary of hematology service of the Republic of Tatarstan

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    The article presents an overview of the development of hematology service in the Republic of Tatarstan. The well-known scientist Nikolay Konstantinovich Goryaev (1875-1943), who worked in Kazan for a long time, began to develop this direction and after passing an internship in Germany proposed an improved device for calculating the blood elements known throughout the world. Adherents of Professor Goryaev continued research in the field of hematology, a blood transfusion station was organized. Professor S.I. Sherman proposed new methods of diagnosis and treatment of B12 deficiency anemia. Professor Sh.I. Ratner studied the changes in the blood picture in diseases of the abdominal cavity. The first 15 specialized hematological beds were opened in 1968 in the hospital named “Old Clinic”. The physician who treated such patients was Rakhil Sholomovna Dashevskaya, PhD. At present, hematology service is provided by three hospitals in Kazan, hematological and therapeutical beds in Naberezhnye Chelny and Nizhnekamsk, outpatient hematology service in Zelenodolsk. In recent years, the introduction of stem cell therapy has begun, and modern combined methods of chemotherapy have been introduced

    Double-Pionic Fusion of Nuclear Systems and the ABCEffect -- Aproaching a Puzzle by Exclusive and Kinematically Complete Measurements

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    The ABC effect - a puzzling low-mass enhancement in the ππ\pi\pi invariant mass spectrum - is well-known from inclusive measurements of two-pion production in nuclear fusion reactions. Here we report on first exclusive and kinematically complete measurements of the most basic double pionic fusion reaction pndπ0π0pn \to d \pi^0\pi^0 at 1.03 and 1.35 GeV. The measurements, which have been carried out at CELSIUS-WASA, reveal the ABC effect to be a (ππ)I=L=0(\pi\pi)_{I=L=0} channel phenomenon associated with both a resonance-like energy dependence in the integral cross section and the formation of a ΔΔ\Delta\Delta system in the intermediate state. A corresponding simple s-channel resonance ansatz provides a surprisingly good description of the data

    Polarisation of the omega meson in the pd-->3He+omega reaction at 1360 and 1450 MeV

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    The tensor polarisation of omega mesons produced in the pd-->3He+omega reaction has been studied at two energies near threshold. The 3He nuclei were detected in coincidence with the pi0pi+pi- or pi0gamma decay products of the omega. In contrast to the case of phi meson production, the omega mesons are found to be unpolarised. This brings into question the applicability of the Okubo-Zweig-Iizuka rule when comparing the production of vector mesons in low energy hadronic reactions.Comment: 11 pages, 4 figure

    Production of eta and 3pi mesons in the pd->3HeX reaction at 1360 and 1450 MeV

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    The cross sections of the pd -> 3He eta, pd -> 3He pi0 pi0 pi0 and pd -> 3He pi+ pi- pi0 reactions have been measured at beam kinetic energies T_p= 1360 MeV and T_p= 1450 MeV using the CELSIUS/WASA detector setup. At both energies, the differential cross section dsigma/dOmega of the eta meson in the pd -> 3He eta reaction shows a strong forward-backward asymmetry in the CMS. The ratio between the pd -> 3He pi+ pi- pi0 and the pd -> 3He pi0 pi0 pi0 cross sections has been analysed in terms of isospin amplitudes. The reconstructed invariant mass distributions of the pi-pi, 3He-pi and 3He-2pi systems provide hints on the role of nucleon resonances in the 3pi production process.Comment: Shorter version accepted to EPJA 10 pages 14 figure

    The pd --> ^3He eta pi0 reaction at T_p = 1450 MeV

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    The cross section for the pd --> ^3He eta pi0 reaction has been measured at a beam energy of 1450 MeV using the WASA detector at the CELSIUS storage ring and detecting one ^3He and four photons from the decays of the two photons. The data indicate that the production mechanism involves the formation of the Delta(1232) isobar. Although the beam energy does not allow the full peak of this resonance to be seen, the invariant masses of all three pairs of final state particles are well reproduced by a phase space Monte Carlo simulation weighted with the p-wave factor of the square of the pi^0 momentum in the ^3Hepi^0 system.Comment: 10 pages, 5 figure
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