А.А. Терехин, В.В. Глаголев, В.П. Ладыгин, С.М. Ладыгина

1. ИЗМЕРЕНИЕ ДИФФЕРЕНЦИАЛЬНОГО СЕЧЕНИЯ И ВЕКТОРНОЙ АНАЛИЗИРУЮЩЕЙ СПОСОБНОСТИ РЕАКЦИИ УПРУГОГО dp-РАССЕЯНИЯ ПРИ ЭНЕРГИИ 2 ГэВ А.А. Терехин, В.В. Глаголев, В.П. Ладыгин, С.М. Ладыгина Объединенный институт ядерных исследований, Дубна, Россия ИТЭФ, 2011

2. Thedp-elastic scatteringatsmall anglesat high energies The interest tostudydp-elastic scatteringat small angles at high energies are defined by thevariedreasons . • Deuteron is the simplest system which consistsof two nucleons. It has spinequal to 1. This feature allows to perform the various polarization experiments.At the same time deuteron has relatively simple structure. It makes possible to test theory of scattering processes. • Large valuesof the analyzing powers allow to use this reaction for the efficient polarimetryof the deuteron beam at 270-2000 MeV.

3. The angular dependence of the vector analyzing power Ay and differential cross section for dp-elastic scattering at 2 GeV are reported in this presentation. The data were obtained using 1 m hydrogen bubble chamber at JINR (Dubna). • The results are compared with the data at ANL (Argonne) and with the theoretical calculations based on the relativistic multiple scattering theory.

4. Losses of theevents in the region of small momentum transfers • The losses of the events in the region of small momentum transfers appear due to methodical reasons. They are related both with the impossibility to observe the tracks with the momentum less than 80 MeV/c and the tracks orientation in the photo-camera direction.

5. Example of the R value distribution for the angular interval 12° <θ* <14° in the cms. For each angular interval parameters of the function p0 + p1sin(φ) was determined

6. Evaluation of the vector polarization of an accelerated beam was performed using the events of the reaction dp → ppn. The deuteron beam polarization was estimated as:py = 0.488 ± 0.061[1]by the measuring of the azimuthal asymmetry of quasielastic scattering using the data on the analyzing powers for elastic np-and pp-scattering at the corresponding energy Figure 4. Distribution of events over the azimuthal angle Figure 5.Analyzing power for elasticnp-and pp-scattering [1] Glagolev V.V. et al. // Z. Phys. A356 (1996) 183.

7. The events obtained both from polarized and unpolarized deuterons beams was used for calculation of the differential cross section. Losses in another reactions were negligible. The millibarn equivalent of the events was estimated as C = 0.0003342 ± 0.0000007mb/event [2].The cross section was calculated using the formula: [2] Bugg D.V. et al. // Phys. Rev. Lett. - 1996. - 146. - Pp. 980-992.

8. The theoretical predictions have been obtained in the relativistic multiple-scattering-theory frame [3]. The single scattering and double scattering contributions into the reaction amplitude were taken into account. Since ONE term gives considerable contribution only at backward angles, this term was not included into consideration. [3] Ladygina N.B. // Eur. Phys. J. A42 (2009) 91.

9. Differential cross section Solid squares – this work. Empty triangles - data from Bennett G. W. et al. Phys. Rev. Lett. 1976. V.19 P. 387-390.

10. Differential cross section Empty boxes - this work. The solid circles– data from Bennett G. W. et al. Phys. Rev. Lett. 1976. V.19 P. 387-390.

11. Solid triangles – this work Empty squares - data obtained atANL. Analyzing powers

12. Analyzing powers Empty circles – this work The solid circles - data from M.Haji-Saied et al., Phys.Rev.C 36 (1987) pp.2010-2017. Empty squares - from P.K. Kurilkin et al., Int.J.Mod.Phys. A24:530-533,2009.

13. Conclusion • Vector analyzing power Ay and differential cross-section of dp-elastic scattering at the deuteron energy 2.0 GeV and at the scattering angles 100-350 in the cms were obtained. • The results agree with experimental data at Argonne (ANL) and with the calculations of multiple scattering theory taking into account the double scattering.

14. Thank you for attention

15. False asymmetry • The value of p0 doesn’t exceed 5% andis equal top0 = -0.0250.014.

16. Events lossesfor the elastic dp-scattering in the t-distribution