Impact parameter resolution study for ILC detector

Tomoaki Fujikawa (Tohoku university)

ACFA Workshop in Taipei

Nov. 11 2004

Outline

Study the pair ee background hit rate for vertex detector with various B fields. (tool:CAIN,Jupiter)

Obtain the impact parameter resolutions with optimized radii. (tool:TRACKERR)

Optimize the vertex detector radii for each B field.

Pair background hit rate studySimulation tools

Monte-Carlo program for the beam-beam interaction. (by Yokoya-san)Included interactions are…

・JupiterJLC Uniform Particle Interaction and Tracking EmulatoR.

GEANT4 based full simulator for ILC (under construction…)

CAIN

photon) virtualmeans ̀(`

` ̀ ̀` Lifshitz-Landau

`` Heitler -Bethe

Wheeler -Breit

ee

ee

ee

(for ee pair background (dominant) generation)

(for pair background hit rate estimation)

Beam parameters (input parameters for CAIN)

)(/104.3

)(3.0 ),(5 (553

)(03.0 ,)(10

(/train)2820n (/bunch),102.0 Ne GeV,500E

234

zyx

yx

b10

CM

scmL

mmnmnm),

mm

Beam parameters are similar to those in the TESLA TDR.

crossing angle = 7mrad.

Detector configuration (for the Jupiter)

Detector is constructed with the Beam pipe, Vertex detector (Ladder construction), Intermediate tracker, Mask, etc. and base geometry is “Old” one. (Namely, designed for “Warm” machine.)

The configuration of the vertex detector

0.4cm islayer innermost and pipe beambetween distance the

) layers4( 1.2cm islayer each between distance the

300 Thickness

coverd are 9.0|cos|hasch region whi the

m

These conditions are applied to estimate pair background hit rate as first layer radius is varied.

Pair background hit rate for the vertex detector1.hit point uniformity (for 1st. layer)

Z

0.9 |cos|

We can use the average hit rate to estimate the occupancy.

B = 3tesla, R1 = 1.2cm.

region. 9.0|cos| within uniform ison distributiHit

Z vs. phi

2. Number of fired pixels per track hit (for 1st. layer)

Number of fired pixel per track hit

Number of fired pixels per 1 track passage is about 3.7. (independent of radius and B field)

m)30 region sensitive theof thickness

m,25 m25 size pixel(sensor

3. Determination of first layer radius

20 readouts per train

3.7 fired pixels per track hit

Pixel occupancy(%) = hit rate (/bunch/cm2) 0.326

Set the first layer radius such that its pixel occupancy = 0.5%

0.5 % occupancy occurs at

3/))2(1exp(0)( pxpxppxf fit function:

tesla)(5 cm 0.0291.554R1

tesla)(4 cm 028.01.694R1

tesla)(3 cm 0.0341.920R1

3 tesla 4 tesla 5 tesla

First layer hit rate vs. first layer radius

Impact parameter resolutions

Use TRACKERR program (also momentum resolution).

Assume pions.

TRACKERR:

FORTRAN program to calculate tracking error matrix with using cylindrically symmetric system.

Energy loss, energy loss fluctuation and multiple scattering effects are included. Track fitting uses Kalman filter.

Detector configurations for TRACKERR

3 tesla 4 tesla 5 teslaBeam pipe (Be)

VTX detector (Si pixel)

IT (Si strip)

TPC

5):2:93

CH:CO:(Ar 42

m250 500, (dBP) thickness, (cm) 0.4RR VTX1bp μ

m50 100, 300, (dVTX) thicknessm,2σ

(4layers), 1.2cm layer each between distance

cm92.1R VTX1 1.69cm 1.55cm

m300 thicknessm,10σ

(5layers), 7cm layer each between distance 3cm,RR

rφ

VTX4IT1

45cm R (2mm,6mm),y)(x,:size Pad m,150σ innerrφ

200cm R outer 160cm 130cm

Impact parameter resolutions of the r-phi plane

case m50 dVTX m,250 dBP :ex

required.) are m10B and m5A

./sinB/P)(Arelation for the

parametersfit are B andA table,bellow in the(

322

Impact parameter resolutions are mostly the same for each magnetic field case. (true for other configurations with different thickness for BP and VTX detector.)

m)( resolution IP vs.P(GeV/c) 90 anglepolar at m)( sresolutionparameter Impact

P = 1.0GeV/ c P = 10GeV/ c P = 100GeV/ c A(micron) B(micron)B = 3tesla 8.84 2.47 1.39 1.44 11.12B = 4tesla 7.79 2.34 1.43 1.49 9.56B = 5tesla 7.16 2.27 1.48 1.53 8.66

Other configuration results are as follows (at polar angle = 90 deg.):

small. quite are sdifference But the cases. 5tesla 4, B

nbetter tha is case 3tesla B 30GeV/c,~ PFor

90 anglepolar at m)( sresolutionparameter Impact

For P = 1GeV/c 3tesla is worse than 4(5) tesla by 12.0(19.2) %.

For P = 10GeV/c 3tesla is worse than 4(5) tesla by 6.4(8.8) %.

dBP (micron) dVTX(micron) B (tesla) P = 1.0GeV/ c P = 10GeV/ c P = 100GeV/ c A(micron) B(micron)3 16.22 3.33 1.44 1.33 22.314 14.24 3.08 1.47 1.38 19.385 13.03 2.94 1.52 1.37 18.453 10.57 2.69 1.40 1.42 13.694 9.32 2.52 1.44 1.47 11.835 8.56 2.44 1.49 1.49 10.963 8.84 2.47 1.39 1.44 11.124 7.79 2.34 1.43 1.49 9.565 7.16 2.27 1.48 1.53 8.66

500 300

100

50

250

Momentum resolutions

case m50 dVTX and m250 dBP:ex

P/ resolution momentum vs.P(GeV/c) P

Momentum resolution is better for high B at low P, and better for low B at high P.

P = 1.0GeV/ c P = 10GeV/ c P = 100GeV/ cB = 3tesla 1.50E- 03 1.38E- 03 3.82E- 03B = 4tesla 1.40E- 03 1.50E- 03 4.29E- 03B = 5tesla 1.35E- 03 1.75E- 03 5.10E- 03

90 anglepolar at P)/( sresolution Momentum P

Other configuration results are as follows (at polar angle = 90 deg.):

90 anglepolar at P)/( sresolution Momentum P

Momentum resolution is better for high B at low P, and better for low B at high P.

dBP (micron) dVTX(micron) B (tesla) P = 1.0GeV/ c P = 10GeV/ c P = 100GeV/ c3 1.50E- 03 1.38E- 03 3.83E- 034 1.42E- 03 1.51E- 03 4.31E- 035 1.37E- 03 1.78E- 03 5.12E- 033 1.51E- 03 1.38E- 03 3.82E- 034 1.41E- 03 1.50E- 03 4.30E- 035 1.36E- 03 1.76E- 03 5.10E- 033 1.50E- 03 1.38E- 03 3.82E- 034 1.40E- 03 1.50E- 03 4.29E- 035 1.35E- 03 1.75E- 03 5.10E- 03

300

100

50

500

250

Comparison with other detector configurations

1. TESLA detector:

detectors) above as same are etc. size Pad ,(

170cm radiusouter 32cm, radiusinner :TPC

m300 thicknesslayers),-(2 30cm 16cm,R :strip) IT(Si

m300 kness thic

layers),-(5 6.0cm 4.8cm, 3.7cm, 2.6cm, 1.5cm,R:pixel) VTX(Si

m500 thicknesscm,4.1R :BP

4teslaB

IT

VTX

bp

Comparison between TESLA and 3 tesla case

m)300 dVTX m,500 dBP(

P = 1.0GeV/ c P = 10GeV/ c P = 100GeV/ c A(micron) B(micron)TESLA 13.22 2.86 1.47 1.60 15.95

GLD 16.22 3.33 1.44 1.33 22.31

90 anglepolar with m)( sresolutionparameter Impact

Comparison between TESLA and 3 tesla case

m)300 dVTX m,500 dBP(

P = 1.0GeV/ c P = 10GeV/ c P = 100GeV/ cTESLA 1.36E- 03 1.21E- 03 4.16E- 03GLD 1.50E- 03 1.38E- 03 3.83E- 03

90 anglepolar with P)/( sresolution Momentum P

2.New VTX detector configuration (proposed by Sugimoto-san):

detector) above as same are etc. IT for the s(condition

m50 s thicknes

,doublets))layer (3 layers-(6 5.0cm 4.8cm, 3.2cm, 3.0cm, 2.2cm, 2.0cm, R VTX

Layer

Polystyrene foamVTX detector

Comparison between double and single layer (3 tesla)

m) 50 dVTX m, 250 (dBP

P = 1.0GeV/ c P = 10GeV/ c P = 100GeV/ c A(micron) B(micron)double layer 11.18 2.40 1.18 1.29 12.78single layer 8.84 2.47 1.39 1.44 11.12

90 anglepolar with m)( sresolutionparameter Impact

Comparison between double and single layer (3 tesla)

m) 50 dVTX m, 250 (dBP

90 anglepolar with P)/( sresolution momentum P

P = 1.0GeV/ c P = 10GeV/ c P = 100GeV/ cdouble layer 1.50E- 03 1.38E- 03 3.80E- 03single layer 1.50E- 03 1.38E- 03 3.82E- 03

Other configuration results:

90 anglepolar with P)/( sresolution momentum P

Momentum resolutions are mostly the same as single layer case, but impact parameter resolutions are different. (single layer case does not have support design yet.)

90 anglepolar with m)( sresolutionparameter Impact

m) 50 dVTX m, 250 (dBP

B (tesla) P = 1.0GeV/ c P = 10GeV/ c P = 100GeV/ c A(micron) B(micron)3 11.18 2.40 1.18 1.29 12.784 11.15 2.40 1.25 1.34 12.865 11.14 2.42 1.34 1.38 12.853 8.84 2.47 1.39 1.44 11.124 7.79 2.34 1.43 1.49 9.565 7.16 2.27 1.48 1.53 8.66

double layer

single layer

B (tesla) P = 1.0GeV/ c P = 10GeV/ c P = 100GeV/ c3 1.50E- 03 1.38E- 03 3.80E- 034 1.41E- 03 1.50E- 03 4.27E- 035 1.36E- 03 1.75E- 03 5.08E- 033 1.50E- 03 1.38E- 03 3.82E- 034 1.40E- 03 1.50E- 03 4.29E- 035 1.35E- 03 1.75E- 03 5.10E- 03

double layer

single layer

Summary and Plan

Impact parameter resolution and momentum resolution are mostly the same in each B field case. (More detailed study (namely, b- and c-taging efficiency study) is needed to estimate the best B field.)

Thickness of the detector components are quite important to obtain the good impact parameter resolution.

Plan

Summary

Estimate the impact parameter resolutions (and more) by using a full simulator. (To do so, development of the simulator is necessary…)