The vector Ay and tensor analyzing powers Ayy and Axx for dp-elastic scattering were measured at the energy of 800 MeV and at the angular range from 60° to 135° in the center-of-mass system at the JINR Nuclotron. The experimental data are compared with the calculations obtained within framework of relativistic multiple scattering approac

Averyanov, A. V.

Chernykh, E. V.

Enache, D.

Mezhenska, O.

Skhomenko, Y. T.

English

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AIP Conference Proceedings 2163, 030011 (2019); https://doi.org/10.1063/1.5130097 2163, 030011© 2019 Author(s).Measurement of the vector and tensoranalyzing powers for dp-elastic scattering atthe energy of 800 MeVCite as: AIP Conference Proceedings 2163, 030011 (2019); https://doi.org/10.1063/1.5130097Published Online: 22 October 2019Olena Mezhenska, Alexander V. Averyanov, Evgenii V. Chernykh, Dan Enache, Yurii V. Gurchin, AlexanderYu. Isupov, Marian Janek, Julia-Tamara Karachuk, Anatolii N. Khrenov, Dmitrii O. Krivenkov, Pavel K.Kurilkin, Vladimir P. Ladygin, Nadezhda B. Ladygina, Alexei N. Livanov, Semen M. Piyadin, Sergee G.Reznikov, Yaroslav T. Skhomenko, Arkadiy A. Terekhin, Alexei V. Tishevsky, Tomozumi Uesaka, JozefUrban, and (DSS Collaboration)ARTICLES YOU MAY BE INTERESTED INAnalysis of the rare decay K+ → μ+ vμ+ μ−AIP Conference Proceedings 2163, 030001 (2019); https://doi.org/10.1063/1.5130087A “vector finder” approach to track reconstruction in the inner tracking system of MPD/NICAAIP Conference Proceedings 2163, 060006 (2019); https://doi.org/10.1063/1.5130112Study of the BM@N GEM/CSC tracking system performanceAIP Conference Proceedings 2163, 030003 (2019); https://doi.org/10.1063/1.5130089Measurement of the Vector and Tensor Analyzing Powers for Dp-elastic Scattering at the Energy of 800 MeV Olena Mezhenska1,a) , Alexander V. Averyanov2, Evgenii V. Chernykh2,             Dan Enache3, Yurii V. Gurchin2, Alexander Yu. Isupov2, Marian Janek4,          Julia-Tamara Karachuk2,3, Anatolii N. Khrenov2, Dmitrii O. Krivenkov2,          Pavel K. Kurilkin2, Vladimir P. Ladygin2, Nadezhda B. Ladygina2,                  Alexei N. Livanov2, Semen M. Piyadin2, Sergee G. Reznikov2,                    Yaroslav T. Skhomenko2,5, Arkadiy A. Terekhin2, Alexei V. Tishevsky2, Tomozumi Uesaka6, and Jozef Urban1 (DSS Collaboration) 1Pavol Jozef Šafárik University in Košice, Šrobárova 2, 041 80, Košice Slovak Republiс 2 Joint Institute for Nuclear Research, 6 Joliot-Curie, 141980, Dubna, Moscow region, Russia 3National Institute for R&D in Electrical Engineering ICPE-CA, 313 Splaiul, District 3, 030138, Bucharest, Romania 4Physics Department, University of Žilina, Univerzitná 1, SK 01026, Žilina, Slovak Republic 5Belgorod State National Research University, 85, Pobedy St., 308015, Belgorod, Russia  6Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, 351-0198, Wako, Saitama, Japan .  a) Corresponding author: olena.mezhenska@student.upjs.sk  Abstract. The vector Ay and tensor analyzing powers Ayy and Axx for dp-elastic scattering were measured at the energy of 800 MeV and at the angular range from 60° to 135° in the center-of-mass system at the JINR Nuclotron. The experimental data are compared with the calculations obtained within framework of relativistic multiple scattering approach.  INTRODUCTION The study of nuclear reactions involving deuterons has always played an important role in the development of ideas about the structure of the nucleus and the dynamics of nuclear interactions. At the new stage of development of nuclear physics, the study of processes involving the deuteron will undoubtedly help to solve many actual relativistic problems of nuclear physics. At the present, a lot of data on the deuteron in deuteron induced reactions obtained by electron and hadron beams has been accumulated [1-2]. Over the past decades, several experimental groups have accumulated data on polarization observables in pd - and nd - elastic scattering, as well as in deuteron-breakup reactions on a nucleon [3-6] in a wide energy range (108 – 300 MeV/nucleon). Most of them were associated with testing the two-nucleon (2N) interaction models and detecting the effect of three-nucleon forces (3NF). Currently, there is a number of phenomenological two-nucleon models that describe the experimental data on NN scattering for energies below the pion formation threshold with fairly good accuracy.  Proceedings of the 23rd International Scientific Conference of Young Scientists and Specialists (AYSS-2019)AIP Conf. Proc. 2163, 030011-1–030011-5; https://doi.org/10.1063/1.5130097Published by AIP Publishing. 978-0-7354-1908-7/$30.00030011-1However, these NN forces fail to describe experimental binding energies of few nucleon systems. Inclusion of the three-nucleon forces (3NFs) into the calculations, can remedy the discrepancies between the experimental data and the theoretical calculation [7].2NF and 3NF effects can be studied using polarized observables in deuteron-proton elastic scattering and deuteron – proton breakup.  In the present work new results on the analyzing powers Ay, Ayy and Axx for dp elastic scattering measured at the energy of 800 MeV and in angular range from 60° to 135° are reported. They are compared with the results of theoretical prediction.EXPERIMENTAL PROCEDUREThe experiment was performed at the Internal Target Station (ITS) at Nuclotron [8], Laboratory of High Energy Physics of Joint Institute for Nuclear Research. ITS is well suited for the study of the d − p interaction reactions at large angles in the center-of-mass system. The experiment consisted of the deuteron beam polarization measurement at the energy of 270 MeV [9] and the analyzing powers measurement at the energy of 800 MeV. Polarized deuterons were provided by polarized ion source SPI (polarized ion source). The linear accelerator LU-20 was used as the injector of Nuclotron. In current experiment two targets were used (polyethylene film 10 μm sheet and carbon wire). Carbon wire has been used to estimate the background. A detector support has been placed downstream of the ITS. 39 scintillation counters based on Hamamatsu PMTs were placed in the horizontal and vertical planes. There are eight proton detectors placed on the right, left and upside with respect to the ITS and only four detectors are placed on the bottom side, due to the space limitations. One pair of counters has been used for pp quasi-elastic scattering as the intensity monitor. The detection of the dp elastic scattering events has been done by the coincident measurement of deuteron at the angular range of 60°-135° in the center-of-mass system.The analyzing powers Ay, Ayy and Axx has been measured at sixteen different angles defined by the position of the counters placed in the horizontal and fifteen different angles defined by the position of the counters placed at the vertical planes.Selection of the dp elastic scattering events has been done by the kinematical coincidence of the scattered deuterons and recoil protons [10].RESULTS OF THE MEASUREMENTSThe angular dependencies of the vector Ay and tensor Ayy, Axx analyzing powers in dp elastic scattering at the energy of 800 MeV are presented at Fig. 1. The results obtained at ITS at Nuclotron at the CH2 target denoted by the full symbols. They are compared with the theoretical calculations performed within the relativistic multiple scattering expansion formalism. The dot-dashed (gray) curve represents the results of those calculations which takes into account one-nucleon exchange (ONE) and single scattering (SS) term. The calculation, witch obtain a double scattering is given by the dashed (blue) curve [11]. The red curve corresponds the calculation with ∆-isobar excitation included [12].It can be seen in (Fig. 1a) that the vector analyzing power has negative values at all angles and none of the models reproduce the behavior of the Ay quantitatively. This can be associated with insufficiently accurate inclusion of 3NF into the calculations. The tensor analyzing power Ayy in dp - elastic scattering (Fig. 2b) has large values at small angles in the center-of-mass system (> 80°).  The tensor analyzing power Axx has large negative values at angles up to 75° (Fig. 1c).It is shown that the model which includes only one-nucleon exchange and single scattering is suitable for describing the behavior of tensor analyzing power Axx at all angular range but does not repeat the behavior of Ay and Ayy. Inclusions in the theory of double scattering and ∆-isobars improve the description of Ayy experimental data obtained at central scattering angles.In the next step, the angular dependences of the vector and tensor analyzing powers will be obtained for thedeuteron-hydrogen reaction. The graphical cuts on the correlation of the energy losses for deuteron and proton obtained at CH2 target (Fig.2a) and the projection at the X – axis (Fig.2b) have been done. The same cuts were applied to the Carbon spectra. After that, the C12 normalization coefficient will be obtained by using the least square method. Then the procedure of CH2 – C subtraction will be performed.030011-2a)b)c)FIGURE 1. Angular dependencies of the vector Ay (a) and tensor Ayy (b), Axx (c) analyzing powers for the dpelastic scattering at 800 MeV. The curves are described in the text.030011-3a) b)FIGURE 2. The procedure of CH2 – C subtraction. a) The correlation of the energy losses in plastic scintillators for proton and deuteron (ADC spectra). The solid lines represent a graphical cut for the selection of dp-elastic scattering events; b) The projection of ADC spectra at the X – axis.CONCLUSIONSThe vector Ay and tensor Ayy, Axx analyzing powers for the dp elastic scattering have been measured for the first time on Internal Target Station of the JINR Nuclotron at the energy of 800 MeV and in the angular range from 60◦ to 135◦ in the center-of-mass system. The obtained data are compared with theoretical predictions obtained using relativistic multiple scattering model.Some deficiencies in the description of the analyzing powers at the energy of 800 MeV require the consideration of additional mechanisms, for instance, 3NFs. Since present 3NFs models cannot improve the agreement with the data obtained at this energies, new models of 3NF’s should be considered.ACKNOWLEDGMENTSThe authors thank the Nuclotron staff for providing good conditions of the experiment. They thank A.S. Belov, V.B. Shutov and V.V Fimushkin for the tune of the SPI [13]. They express the gratitude to S.N. Bazylev, V.I. Maximenkova, I.V. Slepnev, V.M. Slepnev and A.V. Shutov for the help during the preparation of the detector and DAQ system. The work has been supported in part by the RFBR under grant No19-02-00079a, by the Ministry ofEducation, Science, Research, and Sport of the Slovak Republic (VEGA Grant No. 1/0113/18), by JINR-SlovakRepublic and JINR-Romania scientific cooperation program sin2016-2018.REFERENCES1. C.E. Carlson, et al, Ann. Rev. Nucl.Part. Sci. 47, 395-428 (1997).2. R. Gilman, et al, J.Phys. G: Nucl. Part. Phys 28, R37-R116 (2002).3. K. Sekiguchi, et al., Phys. Rev. C 65, 034003 (2002).4. K. Ermisch, et al., Phys. Rev. C 71, 064004 (2005).5. K. Hatanaka, et al., Phys. Rev. C 66, 044002 (2002).6. N. Kalantar-Nayestanaki, J. Mulder, and J. Zijlstra, Nucl. Instr. and Meth. Phys. Res. A 417, 215 (1998).7. S. Coon, M. Scadron, P. McNamee, B.R. Barrett, D. Blatt, B. McKellar, Nucl. Phys. A 317, 242 (1979).8. A.I. Malakhov, Nucl. Instrum. Meth. A 440, 320 (2000); Yu.S. Anisimov, et al., Proc. of the 7 Intern.Workshop on Relativistic Nuclear Physics, Stara Lesna, Slovak Republic (2003), p. 1179. Ya.T. Skhomenko. EPJ Web of Conferences 204, 10002 (2019).10. O. Mezhenska. EPJ Web of Conferences 204, 10001 (2019).11. N.B. Ladygina, Eur.Phys. J.A 42, 91 (2009)12. N.B. Ladygina, Eur.Phys.J. A 52, 199 (2016)13. V.V. Fimushkin, et al., Eur.Phys.J. ST 162, 275 (2008).030011-4

Measurement of the vector and tensor analyzing powers for Dp-elastic scattering at the energy of 800 MeV

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Measurement of the vector and tensor analyzing powers for Dp-elastic scattering at the energy of 800 MeV

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