Vector analyzing powers of deuteron-proton elastic scattering and breakup at 130 MeV

Set of vector analyzing power data of the $\vec{d}p$ elastic scattering and ${}^{1}H(\vec{d},pp)n$ breakup reactions at 130-MeV deuteron beam energy has been measured in the domain of very forward polar angles. The results are compared with theoretical predictions originating from various approaches: realistic nucleon-nucleon (NN) potentials and the NN potentials combined with a three-nucleon force (3NF) model and with predictions based on the ChPT framework. In case of the breakup process, none of the theoretical calculations reveal sensitivity to any of the dynamical effects such as 3NF or Coulomb interaction and they describe the experimental data equally well. For the elastic scattering, the Coulomb correction appears not negligible at very small ${\theta }_d^{\text{c.m.}}$. The effect seems to be confirmed by the data.

Figure 1

Vector analyzing power $i{T}_{11}$ for the $d-p$ elastic scattering at 130 MeV: present experiment (red circles), KVI data (full red dots) [22], and earlier data sets: RIKEN data (red triangles) [23] and data from Ref. [24] (violet squares). The investigated areas of the ${\theta }_d^{\text{c.m.}}$ are enlarged. Theoretical predictions of different approaches are specified by the legend.

Figure 2

Examples of the $d-p$ breakup vector analyzing powers $A_x$ and $A_y$ for the same relative azimuthal angle ${\varphi }_{12}={60}^{\circ }$ and for three different combinations (${\theta }_1$, ${\theta }_2$) of the two coincident protons, specified in the upper panels. Green and orange bands represent calculations based on the chiral theories (at N2LO and N3LO, respectively) and the dashed maroon line shows the calculations based on the realistic AV18 potential combined with the Urbana IX 3NF. The rest of the bands and lines are the same as in the Fig. 1.

Figure 3

Quality of description of the vector analyzing power data with various predictions (defined in the legend), expressed as ${\chi }^2$/d.o.f. dependence on combination of the proton emission polar angles.