1. Measurements of the total-cross-section difference Δσ L(np) at 1.39, 1.69, 1.89, and 1.99 GeV
- Author
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F. Lehar, A. A. Lukhanin, A. L. Svetov, M. FingerJr., N. G. Anischenko, N. A. Bazhanov, G. P. Nikolaevsky, A.A. Zhdanov, P. K. Maniakov, V. P. Ladygin, A. D. Kirillov, I. P. Yudin, Alexander Fedorov, V.F. Chumakov, A. A. Nomofilov, R. A. Shindin, T. A. Vasiliev, Vladislav Sharov, O. N. Schevelev, A. B. Neganov, Yu. A. Plis, A. Janata, E. V. Chernykh, A.N. Livanov, L. B. Golovanov, G. M. Gurevich, N. S. Borisov, V.I. Volkov, Yu. P. Polunin, A. A. Morozov, M. Finger, V. A. Krasnov, V. Yu. Prytkov, V. Slunečková, E. I. Vorobiev, V. G. Kolomiets, N.A. Blinov, I.L. Pisarev, V. A. Schedrov, L. P. Chernenko, I.V. Zaitsev, E.V. Komogorov, S. B. Borzakov, V.D. Moroz, L. S. Azhgirey, A. N. Prokofiev, Alexander Kovalenko, G.D. Stoletov, A. de Lesquen, S.A. Averichev, V.N. Matafonov, A.I. Kovalev, S.A. Dolgii, Yu. K. Pilipenko, A.A. Belyaev, Yu. T. Borzunov, L. N. Strunov, V. V. Fimushkin, V.D. Bartenev, S. N. Shilov, A. B. Lazarev, M. Slunecka, Yu. P. Bushuev, A.Yu. Starikov, Yu. A. Usov, P. Krstonoshich, E. S. Kuzmin, M.Yu. Liburg, V.G. Antonenko, P. A. Rukoyatkin, V. N. Zhmyrov, E. A. Matyushevsky, and Tz. Panteleev
- Subjects
Physics ,Nuclear and High Energy Physics ,Nuclotron ,Proton ,Hadron ,Neutron radiation ,Kinetic energy ,Atomic and Molecular Physics, and Optics ,law.invention ,Nuclear physics ,law ,Neutron ,Synchrophasotron ,Nuclear Experiment ,Nucleon - Abstract
New accurate data of the neutron-proton spin-dependent total-cross-section difference ΔσL(np) at the neutron-beam kinetic energies 1.39, 1.69, 1.89, and 1.99 GeV are presented. In general, these data complete the measurements of energy dependence of ΔσL(np) over the Dubna Synchrophasotron energy region. Measurements were carried out at the Synchrophasotron of the Veksler and Baldin Laboratory of High Energies of the Joint Institute for Nuclear Research. The quasi-monochromatic neutron beam was produced by breakup of extracted polarized deuterons. The deuteron (and hence neutron) polarization direction was flipped every accelerator burst. The initial transverse (with respect to beam momentum) neutron polarization was changed to a longitudinal one and longitudinally polarized neutrons were transmitted through the large proton longitudinally polarized target. The target polarization direction was inverted after one to two days of measurements. Four different combinations of the beam and target parallel and antiparallel polarization directions, both oriented along the neutron-beam momentum, were used at each energy. A fast decrease in −ΔσL(np) with increasing energy above 1.1 GeV and a structure in the energy dependence around 1.8 GeV, first observed from our previous data, seem to be well revealed. The new results are also compared with model predictions and with phase-shift analysis fits. The ΔσL quantities for isosinglet state I = 0, deduced from the measured ΔσL(np) values and known ΔσL(pp) data, are also given. The results of the measurements of unpolarized total cross sections σ0tot(np) at 1.3, 1.4, and 1.5 GeV and σ0tot(nC) at 1.4 and 1.5 GeV are presented as well. These data were obtained using the same apparatus and high-intensity unpolarized deuteron beams extracted either from the Synchrophasotron or from the Nuclotron.
- Published
- 2005
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