Micro Vertex Detector Resolution

Wieman
8-June-04

The expected pointing resolution of the STAR micro vertex detector is calculated using the expression found in: http://www-rnc.lbl.gov/~wieman/PointingRequirement.htm
The SVT resolution is calculated in the same manner for comparison.

Multiple scattering angle
from particle properties data book

Xf is fraction of radiation length

Two layer projection error, combining position error component with multiple coulomb scattering:

eq. 2

distance from projection point to first layer

distance from projection point to second layer

position resolution of the pointing detector

Pointing accuracy of the micro vertex detector to the beam. Includes beam pipe contribution of 0.14%X0

Pointing accuracy of the SVT to the beam. Includes beam pipe contribution of 0.28%X0

The micro vertex detector will provide a factor of 10 improvement for STAR

Standard expression for vertex detector projection resolution:

where sum is in quadrature

Micro Vertex Resolution

SVT resolution