9-14 September 2018
University of Ferrara
Europe/Rome timezone

Recent results in the deuteron break-up with high momentum transfer at COSY

10 Sep 2018, 17:20
A8 (Polo degli Adelardi - Via Adelardi, 33)


Polo degli Adelardi - Via Adelardi, 33

Via Adelardi, 33
Parallel Sessions Spin Physics in Nuclear Reactions and Nuclei Spin physics in Nuclear Reactions and Nuclei


Dr Sergey Dymov (INFN)


The hadron reactions with the production of a diproton final state, which is a proton pair $\{pp\}_s$ with small excitation energy, have been studied extensively at ANKE-COSY. These included the break-up process $pd\to \{pp\}_sn$ at high and low momentum transfer, the $pN\to\{pp\}_s\pi$ one pion production, the $pp\to\{pp\}_s\gamma$ reaction and study of the ABC effect in the $pp\to\{pp\}_s\pi\pi$ reaction. The low excitation energy ensures the final $pp$-pair to be in the $^1S_0$ state, thus reducing the number of the partial waves accessible and simplifying the theoretical description of the process. The hard break-up process $pd\to \{pp\}_sn$ in the colinear kinematics has been studied at ANKE in the energy range 0.5-2.0 GeV, where the main reaction mechanisms are the one nucleon exchange (ONE), $\Delta$-excitation and the single scattering (SS). Selection of a diproton in the final state suppresses the $\Delta$ mechanism, allowing one to probe the deuteron structure at short distances. The obtained results, that included the differential cross-section and the vector analysing power, were compared to the model predictions produced with several modern $NN$-potentials. Recently, this study was complemented by the data on the cross section and $A_y$ at 353 MeV, where one expects the dominance of ONE mechanism, what provides an accurate test of the ONE+$\Delta$+SS model. These results, analysed together with the ANKE data on the $pn\to \{pp\}_s\pi^-$ and $pp\to \{pp\}_s\pi^0$ reactions, previously extracted at the same energy, may solve the existing ambiguity in the partial wave analysis of the pion production processes.

Primary author

Dr Sergey Dymov (INFN)

Presentation Materials