Corsika data check (proton)


Results

The CR flux used for the weights

primary particle energy

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

Dot line: without cut
normal line: with DOM#>80

primary particle energy weighted by the CR flux

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

Dot line: without cut
normal line: with DOM#>80

x position of the primary particle at the surface.

Dot line represents events whose hit DOM is above 80. (high energy events)

y position of the primary particle at the surface.

z position of the primary particle at the surface.

x-y position of the primary particle at the surface.

x-z position of the primary particle at the surface.

y-z position of the primary particle at the surface.

cos(zenith angle) of the primary particle.

Dot line represents events whose hit DOM number above 80. (high energy events)

cos(zenith angle) of the primary particle weighted by hte CR flux.

Dot line represents events whose hit DOM number above 80. (high energy events)

azimuth angle of the primary particle.

cos(zenith angle) of the primary particle Vs the energy.

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

cos(zenith angle) of the primary particle Vs the energy with a cut of DOM# > 80.

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

azimuth angle of the primary particle.

cos(zenith angle) of the primary particle.

azimuth angle of the primary particle.

Multiplicity of muons

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

Dot line: without cut
normal line: with DOM#>80

Multiplicity Vs primary energy

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

cos(Zenith angle) Vs Multiplicity of muons

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

Multiplicity of muons weighted by the CR

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

Dot line: without cut
normal line: with DOM#>80

Energy distribution at IceCube detector (in ice)

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

Dot line: without cut
normal line: with DOM#>80

Even though the statistics may not be enough, I would say ECUTS of 1 TeV is fine.

Energy distribution at IceCube detector (in ice) weighted by the CR flux

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

Dot line: without cut
normal line: with DOM#>80

Energy in ice Vs primary energy

You may be convinced that the EUCTS of 1 TeV (blue dots) is fine to use.

cos(zenith angle) Vs energy in ice

cos(zenith angle) Vs energy in ice with a cut of #DOM > 80

Energy distribution at surface

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

Dot line: without cut
normal line: with DOM#>80

Even though the statistics may not be enough, I would also say ECUTS of 1 TeV is fine.

Energy distribution at surface weighted by the CR flux

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

Dot line: without cut
normal line: with DOM#>80

Energy at surface Vs primary energy

You may be convinced that the EUCTS of 1 TeV (blue dots) is fine to use.

Energy at surface Vs energy in ice

The zenith angle dependence

Black: cos(zenith angle) < 0.2
Blue: 0.2 < cos(zenith angle) < 0.4
Red: 0.4 < cos(zenith angle) < 0.6
Magenda: 0.6 < cos(zenith angle)< 0.8
Water: 0.8 < cos(zenith angle) < 1.0

Horizontal particles loose the energy at high energy. This is probably due to limited simulation volume (880m radius), but I think this is fine because those particles beyond the volume will not make so many photons that can reach our detector, but I will check this more.

cos(zenith angle) Vs energy at surface

cos(zenith angle) Vs energy at surface with a cut of #DOM > 80

Energy at surface Vs energy in ice

There is a constant energy loss during the propagation from surface to the detector (~log10(0.2)~30%)

Energy at surface Vs energy in ice

The zenith angle dependence

Black: cos(zenith angle) < 0.2
Blue: 0.2 < cos(zenith angle) < 0.4
Red: 0.4 < cos(zenith angle) < 0.6
Magenda: 0.6 < cos(zenith angle)< 0.8
Water: 0.8 < cos(zenith angle) < 1.0

Horizontal particles loose the energy more during the propagation.

Npe distribution at IceCube detector (in ice) (ECUTS dependence)

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

Dot line: without cut
normal line: with DOM#>80

I don't see any difference due to the threshold. This is probably because the saturation effect of our detector.

Npe distribution at IceCube detector (in ice) (ECUTS dependence)

Black: ECUTS thres 500 GeV
Blue: ECUTS thres 1 TeV
Red: ECUTS thres 2 TeV

Dot line: without cut
normal line: with DOM#>80

Cos(zenith angle) Vs Npe in ice

Cos(zenith angle) Vs Npe in ice

Npe distribution at IceCube detector (in ice) (MinEnergy dependence)

In case of ECUTS 1 TeV. (almost same results in other ECUTS cases.)

Black: MinEnergy thres 50 GeV
Blue: MinEnergy thres 100 GeV
Red: MinEnergy thres 300 GeV
Water: MinEnergy thres 1 TeV

Dot line: without cut
normal line: with DOM#>80

Even though the statistics may not be enough, I would say MinEnergy of 100 GeV is fine.

Npe distribution at IceCube detector (in ice) (MinEnergy dependence)

In case of ECUTS 1 TeV. (almost same results in other ECUTS cases.)

Black: MinEnergy thres 50 GeV
Blue: MinEnergy thres 100 GeV
Red: MinEnergy thres 300 GeV
Water: MinEnergy thres 1 TeV

Dot line: without cut
normal line: with DOM#>80

Npe in ice Vs primary energy (MinEnergy dependence)

small points: without cut
bigger points: with DOM#>80

You may be convinced more that the MinEnergy of 100 GeV (blue dots) is fine to use.

Cos(zenith angle) Vs Npe in ice


Comaprison with observational data

Npe distribution (corresponding to ~62 days)

Corsika data is much less than observed.

data: black
MC: red

Effective area


Systematic study

In ice energy

In ice bundle energy distribution with fits.

The fit line: ECUTS 500 GeV, 1 TeV and 2 TeV from above.

In ice energy Vs ECUTS (around 10^8 GeV)

The systematic energy difference between ECUTS 0 GeV and 500 GeV is 65% by extrapolation.

In ice energy Vs ECUTS (around 10^6 GeV)

The systematic energy difference between ECUTS 0 GeV and 500 GeV is 37% by extrapolation.

surface energy

Surface bundle energy distribution with fits.

The fit line: ECUTS 500 GeV, 1 TeV and 2 TeV from above.

Surface energy Vs ECUTS (around 10^8 GeV)

The systematic energy difference between ECUTS 0 GeV and 500 GeV is 130% by extrapolation.

surface energy Vs ECUTS (around 10^6 GeV)

The systematic energy difference between ECUTS 0 GeV and 500 GeV is 85% by extrapolation.

Npe (ECUTS dependence)

Npe distribution with fits.

The fit line: ECUTS 1 TeV, 2 TeV and 500 GeV from above.

So, the systematic error is within the error.

Npe (MinEnergy dependence)

Npe distribution with fits.

The fit line: MinEnergy 50 GeV, 100 GeV, 300 GeV and 1 TeV from above.

Npe Vs MinEnergy (around 10^5 Npe)

The systematic energy difference between MinEnergy 0 GeV and 50 GeV is 18% by extrapolation.

Npe Vs MinEnergy (around 10^3 Npe)

The systematic energy difference between MinEnergy 0 GeV and 50 GeV is 15% by extrapolation.

Summary

I found the ECUTS of 1 TeV and MinEnergy of 100 GeV reasonable.

(Actually, the ECUTS of 300 GeV is too time consuming to use.)

The systematic error by using these condition is estimated as ~15%.


Keiichi Mase
Last modified: Thu Feb 21 23:51:07 JST 2008