Software/Analysis progress

1
Software/Analysis progress

• Attacking from 2 flanks
• Software it is a kind of formality (I put the
  stuff that Ive written into the formal STAR
  chain)
• Valerie Fine has given me a lot of
  guidance/direct help
• Need to wait for ThomasUllrich to make the
  StEvent official
• 1 set of pedestals (per channel) is stored in
  StarDb
• Using the same software, I now run on DAQ/RAW
  data to directly produce cluster in my style of
  root-tree
• ? produce t distribution from the clusters in
  opposite roman pots

2
Valeries 11 steps to make it into µDST

•  C-structure -gt     1. -gt TTable     2. -gt "new
  StEventltComponentgt( C-structure )"    3. -gt
  StEventltCollectiongt-gt push_back(StEventltComponentgt
  )    4. -gt Write StEvent into .event.root   
  5. -gt Read StEvent .event.root    6. -gt Iterate
  over StEvent to extract StEventltComponentgt    7.
  -gt Convert it to some MuDstltComponentgt    8. -gt
  Fill MuDST TTree.    9. -gt Write .mudst.root
  file    10. -gt Analyze data from .mudst.root
     11. -gt create some smaller MuDst.root

3

• 2 equations for each roman pot on each side of
  the IP
• x a11 x Leffx ?x a13 y a14 ?y
• y a31 x a32 ?x a33 y Leffy ?y
• Combining two sets of them, oned have 4
  equations and 4 unknowns ? solvable
• But it turns out to be tricky for me (due to my
  limited intelligence) and has taken me 24 hours.
• I have also tried an approximate method
• x ? Leffx ?x ? ?x ? x / Leffx
• y ? Leffy ?y ? ?y ? y / Leffy
• From MAD8 manual, actually, so-called?x Px/P0 ,
  ?y Py/P0
• ? cos(?) Pz/P0 or ?
  ?

4
Transport matrices were made looking from IP to
the roman pots !

• The tricky part for me (what signs to change)
• x a11 x Leffx ?x a13 y a14 ?y
• y a31 x a32 ?x a33 y Leffy ?y
• Needed to change signs in the yellow equations
  (only)
• -x -a11 x Leffx ?x a13 y - a14 ?y
• y -a31 x a32 ?x a33 y - Leffy ?y

x for blue (West)
y for blue/yellow
?x
?y
?x
?y
-y
x for yellow (East)
5
Before all these, its all headache to convert
indices to (x,y) coordinates (from Donikas
Setup diagram)

• Eg. here is an extract from my program
• // EHO
• Vpos(0) x01/1000. xEpitch_4svx0.01
  // in m
• Vpos(1) y01/1000. - yEpitch_6svx0.01
  // in m
• // WHI
• Vpos(2) x04/1000. - xWpitch_4svx0.01
  // in m
• Vpos(3) y04/1000. - yWpitch_6svx0.01
  // in m

6
Solutions from 4-dimensional equations.
7
-t 4P02Sin2(?/2) , P0 100. 21557 calculated
from B? and G? 191.500006443 in RampEditor (of
C-AD)
-t distribution from just Leff
-t distribution from solving 4-dimensional
equations