1

LEPS IRS3B analysis Summary

JETER HALL

PNNL

2

PNNL Ntuple Status

20131011 is the latest production tag

Includes:LEPS tree (copied from UH ntuples)

Matching verified for >99% of events in exp 2 and 3, 100% of exp4

Many new variables

Several bugs fixed in CAMAC parsing

Documentation available:https://belle2.cc.kek.jp/~twiki/bin/viewauth/Detector/TOP/TopcafTreeDefs

Documentation for the LEPS variables also now available:https://belle2.cc.kek.jp/~twiki/bin/viewauth/Detector/TOP/BeamTestJune2013ROOTDataFormats

3

ntof

14.7% of events have ntof==1

The timing counter is known to cause significant showeringSee https://www.phys.hawaii.edu/elog/iTOP+Cosmic+Ray+Telescope/130909_200207/ntof.pdf

4

tofid?

tofid is usually 23, ntof==1 cut does cut down on outliers

Red histogram is with ntof==1, right histograms are scaled to have equal heights in the tofid==23 peak

5

ntof

ntof cut does not change the nhit distribution significantly

Red histogram has the ntof==1 cut, as well as requiring tofid==23

6

Mario Plots

7

Mario Plots

Interesting

8

Cut on early hits?

For exp3 and exp4, we don’t expect many hits with times similar to normal incidence (before -101 ns in our photon_time variable)

Interesting nhit correlations between the hits between -120,-101 for exp3, and exp4

Is this correlated with anything in the LEPS data?

nhit_early is the hits countin the time range -120,-101(exp3)

9

Cut on early hits?

For exp3 and exp4, we don’t expect many hits with times similar to normal incidence (before -101 ns in our photon_time variable)

Interesting nhit correlations between the hits between -120,-101 for exp3, and exp4

Is this correlated with anything in the LEPS data?

Red histogram requires <4 hits in the time range -120,-101(exp3)

10

Comparison with MC (exp3)

Nhits still off by ~5 hits

Red histogram requires <4 hits in the time range -120,-101

mean = 19.4 hitsmaxbin = 15 hits

Blue histogram is MC v1.1mean = 11.3 hitsmaxbin = 10 hits

(exp3)

11

Comparison with MC (exp2)

Comparing the time evolution of light. (Using MC v1.2)

More attenuation/diffusion?