Complete set of deuteron analyzing powers for $dp$ elastic scattering at 250–294 MeV/nucleon and the three-nucleon force

A complete high-precision set of deuteron analyzing powers for elastic deuteron-proton ($dp$) scattering at 250 and 294 MeV/nucleon has been measured. These data and previously existing data sets for the cross section at similar energies are compared to the results of three-nucleon Faddeev calculations based on modern nucleon-nucleon ($NN$) potentials alone or combined with two models of three-nucleon forces: the Tucson-Melbourne 99 and Urbana IX. Large discrepancies between pure $NN$ theory and data, which are not resolved by the current three-nucleon forces, were found at c.m. backward angles ${\theta }_{\mathrm{c}.\mathrm{m}.}\gtrsim {120}^{\circ }$ for all the deuteron analyzing powers and the cross section. Because only small relativistic effects were found for the deuteron analyzing powers and the cross section, the inclusion of short-range components of the three-nucleon force is probably required to get a better description of the data.

Figure 1

Schematic view of the experimental setup.

Figure 2

Top view of the BigDpol.

Figure 3

Spectra of light outputs in the scintillation detectors for the scattered deuterons (a) and the recoil protons (b). The deuteron and proton detectors were placed at $25.1^{\circ }$ and $43.0^{\circ }$, respectively. Hatched line region indicates accidental coincidence events estimated by coincidence triggering between adjacent beam bunches. After subtracting accidental coincidence events a two-dimensional plot of the deuteron and proton scintillator detector outputs was obtained (c).

Figure 4

Deuteron analyzing powers $i{T}_{11}$ and $T_{20}$ for $dp$ elastic scattering at 250 and 294 MeV/nucleon. The dark shaded (blue) bands contain predictions of modern $NN$ potentials alone (AV18, CD Bonn, Nijmegen I and II). The light shaded (red) bands result when those potentials are combined with the TM99 3$N$F, properly adjusted to reproduce the ${}^3$H binding energy. The solid curves show the result obtained with the combination AV18 + Urbana IX. The experimental data are shown with open circles.

Figure 5

Deuteron analyzing powers $T_{21}$ and $T_{22}$ for $dp$ elastic scattering at 250 and 294 MeV/nucleon. For description of bands and curves see Fig. 4.

Figure 6

Cross section for 250 and 300 MeV/nucleon. The data shown at 250 MeV/nucleon are $pd$ data (open circles) [18] and $nd$ data (solid circles) [21]. The data shown at 300 MeV/nucleon are $pd$ data at 295 MeV/nucleon (open circles) [47] and $pd$ data at 316 MeV/nucleon (open squares) [48]. For description of bands and curves see Fig. 4.

Figure 7

Deuteron analyzing powers $i{T}_{11}$, $T_{20}$ for $dp$ elastic scattering at 250 and 294 MeV/nucleon. The solid (blue) and dashed (red) curves show the results of nonrelativistic Faddeev calculations with the CD Bonn potential alone and combined with the TM99 3$N$F, respectively. The relativistic calculations based on the CD Bonn potential without Wigner spin rotations are shown with blue (dotted) curves. The red (double-dot-dashed) curves show the relativistic calculations with the TM99 3$N$F included.

Figure 8

Deuteron analyzing powers $T_{21}$ and $T_{22}$ for $dp$ elastic scattering at 250 and 294 MeV/nucleon. For description of curves see Fig. 7.

Figure 9

Cross section for 250 and 300 MeV/nucleon. For description of curves see Fig. 7.