Contribution to Azimuthal Angle Resolution
from Curvature Resolution
<#1567#>Figure<#1567#> 3:
<#1568#>The concept for estimating the effect of curvature resolution
on azimuthal angle resolution.<#1568#>
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The curvature #tex2html_wrap_inline479# and direction in the bending plane is measured at a
``point'' (actually a region in the plane)
rotated from the vertex by an angle #tex2html_wrap_inline481# about the center
of curvature, not at the vertex. To infer the azimuthal angle #tex2html_wrap_inline483#
at the vertex, track must be swum backward through angle
#tex2html_wrap_inline485#. Determination of #tex2html_wrap_inline487# depends on #tex2html_wrap_inline489# and thus on #tex2html_wrap_inline491#. An
error in #tex2html_wrap_inline493# translates directly into an error in #tex2html_wrap_inline495#.
so
where #math41##tex2html_wrap_inline497#. As an approximation,
we take #math42##tex2html_wrap_inline499#.
Note that a side effect of using a straight-line approximation for the
trajectory is that in some cases #tex2html_wrap_inline501# can be greater than
#tex2html_wrap_inline503#, <#196#>i. e.<#196#>, the curving track never reaches the outer radius
obtained from the straight-line approximation. In those cases, the
outer radius is set to #tex2html_wrap_inline505#. This avoids arguments to the inverse sine
greater than one.
