R. Ramazani-Sharifabadi, H. R. Amir-Ahmadi, M. T. Bayat, I. Ciepał, M. Eslami-Kalantari, N. Kalantar-Nayestanaki, St. Kistryn, A. Kozela, M. Mahjour-Shafiei, H. Mardanpour, J. G. Messchendorp, M. Mohammadi-Dadkan, A. Ramazani-Moghaddam-Arani, E. Stephan, and H. Tavakoli-Zaniani

SciPost Phys. Proc. 3, 057 (2020) · published 1 April 2020 | Toggle abstract · pdf

Detailed measurements of vector and tensor analyzing powers of the 2H(d, dp)n breakup process are presented. The data were obtained using a polarized deuteron-beam with an energy of 65 MeV/nucleon impinging on a liquid-deuterium target. The experiment was conducted at the AGOR facility at KVI using the BINA 4Pi-detection system. The focus of this contribution is to analyze data of the dd scattering process in the regime at which the neutron acts as a spectator, which we refer to as the quasi-free (QF) limit. To achieve this, events for which the final-state deuteron and proton are coplanar have been analyzed and the data have been sorted for various reconstructed momenta of the missing neutron. In the limit of vanishing neutron momentum and at small deuteron-proton momentum transfer, the data match very well with measured and predicted spin observables of the elastic deuteron-proton scattering process. The agreement deteriorates rapidly with increasing neutron momentum and deuteron-proton momentum transfer. The results of coplanar configurations in four-body phase space are compared with the results of recent available theoretical calculations based on the Single-Scattering Approximation.

Nurbek Tursunbayev, Yuriy Uzikov

SciPost Phys. Proc. 3, 056 (2020) · published 27 February 2020 | Toggle abstract · pdf

The recent ANKE@COSY data on the differential cross section of reaction $pd \to pd\pi\pi$ demonstrate a peak at invariant mass of the final $d\pi\pi$ system $2.38~GeV$, that corresponds to the isocalar $J^P = 3^+$ dibaryon $D_{03}$, and also enhancement in the distribution over the invariant mass of two final pions. The two-resonance model involving the $t$-channel $\sigma$-meson exchange between the proton and deuteron in the subprocess $pd\to pD_{03}$ and the sequential decays $D_{03}\to D_{12}+\pi$ and $D_{12}\to d +\pi$ was applied to describe the shapes of these distributions with the lowest orbital angular momenta in the corresponding vertices. A possible role of higher orbital momenta in those vertices is studied here.

Yuriy Volkotrub, Jacek Golak, Roman Skibiński, Kacper Topolnicki, Henryk Witała

SciPost Phys. Proc. 3, 055 (2020) · published 27 February 2020 | Toggle abstract · pdf

We use a correlation matrix of two-nucleon (2N) potential parameters to investigate correlations among three-nucleon (3N) observables for the elastic nucleon-deuteron (Nd) scattering process. We employ the up-to-date 2N semilocal momentum-space regularized chiral interactions and the phenomenological OPE-Gaussian potential and using the Faddeev formalism we calculate 3N observables and their correlations. As an example, we present the correlation between the differential cross section and the deuteron analyzing power T20.

Souichi Ishikawa

SciPost Phys. Proc. 3, 054 (2020) · published 27 February 2020 | Toggle abstract · pdf

Elastic and breakup cross sections in nucleon-deuteron scattering at intermediate energies are calculated using a realistic two-nucleon potential and three-nucleon potentials based on the exchange of two pions among three nucleons. Attractive effects of the pion-exchange at medium range region in the three-nucleon potential are recovered by using a shorter range cutoff. It is shown that these effects increase the cross sections at backward angles, which tends to reduce discrepancies between theoretical calculations and experimental data.

Nadezhda Ladygina

SciPost Phys. Proc. 3, 053 (2020) · published 27 February 2020 | Toggle abstract · pdf

We study deuteron- proton elastic scattering in the deuteron energy range between 500 MeV and 2~GeV at the cms scattering angle $\theta^*\ge 140^\circ$. The reaction is considered in the relativistic multiple scattering expansion framework. The four reaction mechanisms are included into consideration: one-nucleon exchange, single scattering, double scattering, and the term corresponding to the delta excitation in the intermediate state. The model is applied to describe the angular dependence of the differential cross section at the deuteron energies of between 880 and 1300 MeV. Also the energy dependence of the differential cross section and polarisation observables such as tensor analyzing power $T_{20}$ and polarization transfer from the deuteron to proton $\varkappa$ are considered at the scattering angle equal to 180$^\circ$. Contributions of the different reaction mechanisms into the reaction amplitude are demonstrated in comparison with the existing experimental data.