Speaker
Description
Spin amplitudes of pN elastic scattering contain fundamental information on the dynamics of the NN-interaction and so far can not be derived from theory. Experimental data from systematic study of spin amplitudes of pp- and pn-scattering are collected in the SAID partial-wave analysis at kinetic energies below 3 GeV and 1.2 GeV, respectively [1]. At higher energies experimental data on spin amplitudes are rather incomplete for pp- and very scarce for pn-scattering, therefore, phenomenological models and corresponding parametrization of pN amplitudes [2-4] are used in analysis. Complete polarization experiment can provide spin amplitudes of pN- scattering, but is very complicated because requires measurement of ten and more observables at each collision energy. On the other hand, an effective test of existing spin pN-amplitudes can be provided by measurement of spin observables of pd-elastic scattering, that is the simplest process which charakteristics can be calculated on the basis of the spin-dependent Glauber theory of multistep scattering [5,6] involving both the pp- and pn-amplitudes.
Asymmetric mode of pd-collision will be not realized at the NICA SPD collider, but the symmetric dd-mode will be done. While the elastic dd-scattering also can be used as a test of pN- helicity amplitudes, this process is more complicated as compared to the pd-pd, and the spin dependent Glauber theory for dd→dd is not yet developed. In this situation we have found that spin observables $A^p_y$, $A_y^d$, $A_{yy}$, $С_{y,y}$ of the dd→ npd reaction for the pole mechanism of the quasi-free pd-elastic scattering are directly related to the corresponding spin observables of the free pd- elastic scattering, for those the spin-dependent Glauber theory [5,6] with existing models of the pN spin amplitudes at suitable energies [3-5] can be applied. Most of these observables a very sensitive to contribution of spin pN amplitudes and therefore a comparison of results of such calculations with expected NICA SPD data on quasi-free pd-scattering will provide an effective test of the phenomenological pN amplitudes [7]. Furthermore, the tensor analyzing power $A_{yy}$ in pd-pd is rather large at non-zero relative momentum of nucleons in the deuteron and much less sensitive to spin pN-amplitudes and, therefore, can be used for tenzor polarimetry at SPD NICA energies. Preliminary Monte-Carlo simulations indicate the feasibility of such measurements at the first stage of the SPD detector and more detailed studies are still being performed.
List of references
[1] R. Arnd, W. Briscoe, I. Strakovsky et al., Phys. Rev. C 76 (2007) 025209.
[2] A. Sibirtsev, J. Haidenbauer, S. Krewald, U.-G.Meissner, Eur. Phys. J. A 45 (2010) 357-372 e-Print: 0911.4637 [hep-ph]
[3] O.V. Selyugin, Phys.Rev.D 110 (2024) 11, 114028 ; e-Print: 2407.01311 [hep-ph].
[4] W.P. Ford, J. van Orden, Phys. Rev. C 87 (2013).
[5] M.N. Platonova, V.I. Kukulin, Phys.Rev.C 81 (2010) 014004, Phys.Rev.C 94 (2016) 6, 069902; (erratum) e-Print: 1612.08694 [nucl-th]
[6] M.N. Platonova, V.I. Kukulin, Eur.Phys.J.A 56 (2020) 5, 132; e-Print: 1910.05722 [nucl-th]
[7] Yu. Uzikov, A. Bazarova, A. Temerbaev, Phys. Part. Nucl. 53 , N2 (2022) 419 .
