Some Plots from Mu2eG4

Goals

- To get a feel for the T-tracker acceptance

- I will just show plots that struck me as being important for pattern recognition

- Will be much more quantitative in the very near future.

Caveats

- The C++, Root learning curve was steep, so I didn’t getas much done as I’d like.

Thanks to Rob for helping out !!!Hogan NguyenJan 5th 2010

From Rob’s Cornell Seminar December 19th 2010

X-Y Straw Hit Location for Signal Electrons from ntuple in Readback.cc

DS Field Strength = -0.5 T

Even Planes Even Sectors Even Planes Odd Sectors

0

2

4

1

3

5

X-Y Straw Hit Location for Signal Electrons from ntuple in Readback.cc

DS Field Strength = -0.5 T

Odd Planes Even Sectors Odd Planes Odd Sectors

02

4

1

3 5

Conversion Electrons Generated with Cos(Polar) = 0.7

PT(Plane=0) = 75 MeV

Radius(Plane=0) = 25 cm

Radius(Plane=35) = 24.95 cm

Orbit radius shrinks by500 microns, or 5x thehit resolution !

energyloss intarget ?

~ 1.8 orbit cycles

Conversion Electrons Generated with Cos(Polar) = 0.5

PT(Plane=0) = 90.9 MeV

Radius(Plane=0) = 30.31 cm

Radius(Plane=35) = 30.19 cm

Orbit radius shrinks by1.2 mm, or 12x thehit resolution !

~ 2.5 orbit cycles

Conversion Electrons Generated with Cos(Polar) = 0.3

Radius(Plane=0) = 33.39 cm

Radius(Plane=35) = 33.13 cm

Orbit radius shrinks by2.6 mm, or 1 straw radius !

Other Configurations

MC doesn’t support transportingbackwards conversion electrons

ie. generating cos(polar) = -0.7 doesn’t work

Asset’s T-tracker Memo V4

Track intercepts exactly 1 panel

2 panels

3 panels

4 panels

At least two panels are requiredto reconstruct x AND y.

Radius 0 panels 1 panels 2 panels > 2 panels

0-38 cm 100% 0 0 0

38-43 cm 0% 50% 50% 0

To do Pattern Recognition,

Need to start with regionswhere track goes through2 panels.

2 panels are needed tomake “seed” hits.

cos(polar) = 0.3

if track enters a station,

95% chance for

entering regions

with at least 2 panels

cos(polar) = 0.7 cos(polar) = 0.5

if track hits a station,

93.6% chance of entering region withat least 2 panels

if track hits a station,

83.5% chance of entering region withat least 2 panels

A Conversion Electron Event

2 mm bins

All stations

Station 12

Station 10

1 mm bins

1 mm bins

For patter recognition, will need to understandthe typical scatter in these points withineach station