Transcript Track finder for CBM silicon tracker stations

Track finder for STS
with conformal mapping
O. Rogachevsky
May 10 2004
GSI
Hits in STS planes
Au + Au (25 GeV/n)
Conformal mapping track finder
2
Conformal mapping
x  x0
y  y0
u 2 ;  2
r
r
r 2  ( x  x0 )2  ( y  y0 )2
xc  x0
1
u( ) 

yc  y0
2 ( yc  y 0 )
Conformal mapping track finder
3
Different momenta mapping
XZ plane
Conformal mapping track finder
UV plane
4
Parameters cutting
Conformal mapping track finder
5
Hit by hit comparison
Conformal mapping track finder
6
Hit by hit comparison
nonhomogeneous
magnetic field
UrQMD 100 events
AuAu at 25 GeV/n
Ntracks ~ 900
Conformal mapping track finder
7
Track reconstruction efficiency
Reconstruction for vertex track only
εhits 
.6
Conformal mapping track finder
8
Summary
 Conformal mapping is very robust track finding
method for non-homogeneous magnetic field
 Results are preliminary and tuning of parameters
is needed