With a Monte Carlo simulation, the momentum resolution
of the HKS was estimated to be 75 keV/
(RMS)
for a spatial resolution of 200
m of
the chambers.
Assuming 1
, it will be 180 keV/ (FWHM) for 1.8 GeV/ beam.
For vertical and horizontal resolutions of the chamber as
150m, the momentum resolution of the Enge spectrometer is estimated to be
93 keV (FWHM).
scattering angle
The uncertainty of the K emission angle is dominated by the
multiple scattering through the materials between the
target and the chambers (uncertainty due to the spatial resolution
of the chambers are less than 0.2 mrad).
Contribution of the following materials are taken into account:
the target (100 mg/cm
), vacuum windows (kevlar 0.008'', mylar 0.005''),
helium bag (100 cm) and chambers (mylar 0.0045'', argon 5.08 cm @ STP).
Total uncertainty of the K angle was estimated to be
3.3 mrad (r.m.s.) for the carbon target.
This angular uncertainty corresponds to 152 keV (FWHM) ambiguity to the
B mass. Similarly, this effect to 
Al
(Si target) will be 64 keV (FWHM).
K assuming Vavilov distribution.
The whole momentum loss in the target will contribute the mass resolution
without any correction.
The average momentum loss of 1.2 GeV/ K in the carbon 100 mg/cm
was 195 keV/ which corresponds to the energy resolution of 180 keV(FWHM).
The results are summarized in Table 5. Present proposed experimental setup will achieve the resolution around 300 keV (FWHM).
| Item | Contribution to the resolution (keV, FWHM) | |||
| Target | C | Si | V | Y |
| HKS momentum | 190 | |||
| Beam momentum |  180 |
|||
| Enge momentum | 93 | |||
| K angle |
152 | 64 | 36 | 20 |
| Target (100 mg/cm) |
180 |
171 |
148 |
138 |
| Overall | 360 |
330 |
320 |
310 |