LPM effect on the IC80 data

Generated by EHE meta project with revision 44789. Based on 20k events. The CMC project was responsible for the LPM calculation. Primary particles thrown to the IceCube volume are electron neutrinos


Event Examples

Because the major energy range (~ 1 EeV) of the GZK events does not show sizable lonitudinal elongation due to the LPM effect, many events look nearly indentical with those without accounting LPM effects. Also note that the line-fit based geometrical reconstrution does not work good even to superhigh energy (~ 10EeV) events with streached out longitudinal profile, which results in no improvement of the GZK sensitivity.

Energy: 0.72 EeV
NPE: 1.48 e6
Cos(Zenith (MC truth)) : -0.2766
Cos(Zenith (First Gs)) : -0.4174

Energy: 1.32 EeV
NPE: 1.09 e6
Cos(Zenith (MC truth)) : -0.2411
Cos(Zenith (First Gs)) : -0.0373

Energy: 8.91 EeV
NPE: 2.88 e6
Cos(Zenith (MC truth)) : 0.9110
Cos(Zenith (First Gs)) : 0.6335


Event Distribution Plots

Categorized in the 4 subgroup in the EHE signal cut, from category A (far left) to D. Refer the paper draft for their difinition. No visible change due to the LPM effects is observed. Note that the line-fit based geometrical reconstruction has a trend to give vertical track geometry to the short and poor events passing outside the IceCube volume (i.e. category B and D).

Correlation of zenith angle - MC truth Vs. First Guess
weighted by the GZK flux

Event distribution on the plane of Npe-Cos(Zenith)
weighted by the GZK flux


Event Rate

No change at all... Using the "GZK 4" flux as a benchmark.

0.188 pm 0.004 /yr (no LPM)

0.193 pm 0.01 /yr (LPM)