The data presented in this section were taken in the KSU ``'' polarimeter. Sitting on the flight path this polarimeter collected data at and . Primary analysis of the laboratory frame spin observables, 's, was done at IUCF by persons other than the author and is presented here to try to get a complete picture of the results from experiments E385 and E387.
The data are the only data from the KSU ``'' polarimeter to be presented. The reason for this is that at the cross section for both the and reaction have dropped to the point that sufficiently few statistics were gathered so as to make results of questionable value. For data it was necessary to bin the data in the quasifree peak by 20 MeV to get acceptable uncertainties. The KSU detector was able to measure the quasifree peak out to a larger energy loss, as can be seen in the data below, because it sat at a shorter flight path than the INPOL detector. This meant the slower neutrons from the tail of the quasifree distribution had time to get to the detector before the fastest neutrons from the following proton pulse arrived. This was useful because at the higher angles the peak of the neutron energy distribution moves to higher energy loss.
The spin observables from the polarized beam are shown in figure along with the relative cross section of the and reactions. Similar results are shown for polarized beam and polarized beam in figures and , respectively.
Figure: Spin-observable results from the
and
reactions at
for an polarized proton beam with MeV. The
excitation spectra are shown at the top. The dashed line show the results
of Faddeev calculations of the spin-observables for the deuterium
reaction. The vertical dotted line indicate the energy loss for free np
scattering.
Figure: Spin-observable results from the
and
reactions at
for an polarized proton beam with MeV. The
excitation spectra are shown at the top. The dashed line show the results
of Faddeev calculations of the spin-observables for the deuterium
reaction. The vertical dotted line indicate the energy loss for free np
scattering.
Figure: Spin-observable results from the
and
reactions at
for an polarized proton beam with MeV. The
excitation spectra are shown at the top. The dashed line show the results
of Faddeev calculations of the spin-observables for the deuterium
reaction. The vertical dotted line indicate the energy loss for free np
scattering.
In general, as with the and data, the measurement of the 's tends to follow the Faddeev calculations [Wit96]. The agreement is not perfect but, for the most part, the trends are the same. The Faddeev calculations for and induced polarization (figure ) at were not available.
The center-of-mass spin observables, 's, are shown in figures and . These results are also compared to the results of Faddeev calculations (shown with the short-dashed line) and to free np scattering (shown with the long-dashed line) from calculations based on the Argonne potential.
Figure: (spin 0) and (spin transverse,
)
spin observables as a function of energy loss at
.
Results from both deuterium and carbon are shown. The short-dashed line
shows the
results of Faddeev calculations of the deuterium spin observables. The
long-dashed line shows the free np scattering results based on the Argonne
potential.
The vertical dotted line indicates the energy loss for free np scattering.
Figure: (spin longitudinal, ) and
(spin transverse, )
spin observables as a function of energy loss at .
Results from both deuterium and carbon are shown. The short-dashed line
shows the
results of Faddeev calculations of the deuterium spin observables. The
long-dashed line shows the free np scattering results based on the Argonne
potential.
The vertical dotted line indicates the energy loss for free np scattering.
The same conclusions drawn based on the center-of-mass spin observables can not necessarily be made with the data. In both transverse observables ( and ) there is a noticeable difference between the deuterium and carbon results, and the deuterium is seemingly consistent with the free np calculations. Interestingly, the results from the Faddeev calculations seem to be doing a worse job of predicting the observables than the free np scattering results based on the Argonne potential.