1

Outline• Highlight in background rates estimation

(Liangjian and Chao)• Impact of fine structures in reactor spectrum

(Xin)• Requirement in Energy resolution (Liang Zhan

and Xin)• Installation/Running of JUNO simulation (Xin’s

experience)• Strategy and Plan (All)

2

Background Summary for Yellow Book

• Db-488

From Liangjian

3From Liangjian

4

Liangjian

Expected Li9/He8 rate 80 per day

5

6

Outline• Highlight in background rates estimation

(Liangjian and Chao)• Impact of fine structures in reactor spectrum

(Xin)• Requirement in Energy resolution (Liang)• Installation/Running of JUNO simulation (Xin’s

experience)• Strategy and Plan

7

Spectrum Comparison

• Obtained six spectra from Dan

8

Strategy Description• In this study, we want to find out if the fine

local structure present in the spectrum can lead to reduction of the sensitivity.

• Therefore, we do not care about the difference in the large structures

• For each histogram (12000 bins for 0-12 MeV)– Rebin 100, find the center and obtain a smooth

spectrum– Calculate the residual between the fine structure

spectrum and the smooth spectrum– Apply this correction to the currently used

spectrum in the fitter

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Fine structure

For different spectrum, it seems that the fine structures are very similar. This is good news, we would have some knowledge of the position of each fine structure, given the knowledge of known beta decay branches

10

Zoom in plot and comparison with MH

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Fitter Hack• Hack Fitter to add in the spectrum distortion

Situation Sanity Check NH w.o. minimization

Sanity Check IH w.o. minimization

Minimize NH Minimize IH

Old Code 0 49.2535 0 14.0458

Updated Code without fine structure

0.002 49.3923 0 14.1221

Updated Code with fine structure

2.59637 52.3633 1.60368 16.9516

Truth is NH. As expected, the impact of the fine structure is quite small. Note: this study does not mean that the impact of the fine structure is absolute small. This study only demonstrate this particular fine structure’s impact is small. Still need to control the large structure, and all kind of small structures

No fine structure: Δχ2 = 14.05 With fine structure: Δχ2 = 15.35

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Try the black curve as an example

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Fitter Hack

• Hack Fitter to add in the spectrum distortionSituation Sanity Check NH Sanity Check IH Minimize NH Minimize IH

Old Code 0 49.2535 0 14.0458

Updated Code without fine structure

0.002 49.3923 0 14.1221

Updated Code with fine structure

12.0385 62.0775 2.71391 18.2485

Similar as before …

No fine structure: Δχ2 = 14.05 With fine structure: Δχ2 = 15.53

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Fitter Check for Precision MeasurementSituation Sin22theta12 Dm232 Dm221

Old code chi2 0 0 0

Old code chi2 for 0.1-sigma change

0.266377 1.63004 0.63255

New code chi2

1.60368 1.60368 1.60368

New code true

0 0 0

New code minimum

-0.02413 -0.00478877 0.025128

New code chi2 for 0.1-sigma change

1.86953 3.2392 2.23986

No fine structure: Δχ2 = 0.266, 1.63, 0.633 With fine structure: Δχ2 = 0.266, 1.64, 0.636Similar to the MH case

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Summary

• Given spectra from Dan with fine local structure, we study the impact to JUNO’s sensitivity– No major effect was observed

• It is still crucial to control the effect of the fine local structure to reduce systematics due to spectra

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Outline• Highlight in background rates estimation

(Liangjian and Chao)• Impact of fine structures in reactor spectrum

(Xin)• Requirement in Energy resolution (Liang)• Installation/Running of JUNO simulation (Xin’s

experience)• Strategy and Plan

17

DB-396 Liang Zhan et al.

• Requirement on energy resolution was studied by Liang et al.

What’s important for the energy resolution is NOT energy resolution @ 1 MeVBut the energy resolution at ~ 2.5 MeV

Sqrt(2.5) ~ 1.6

2 2 2 2 2

22 2 2

(3%)

(3%)

a E b E c E

ca b E

E

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Outline• Highlight in background rates estimation

(Liangjian and Chao)• Impact of fine structures in reactor spectrum

(Xin)• Requirement in Energy resolution (Liang)• Installation/Running of JUNO simulation (Xin’s

experience)• Strategy and Plan

19

Current Status of Simulation• Simulation installed (Thanks to Tao)– http://juno.ihep.ac.cn/mediawiki/index.php/Offline:Installation– Need to

• Cleanup global environment• Run ./install-J13

(http://www.phy.bnl.gov/~xqian/juno_reading/install-J13v1r1.sh)• Source juno_tcsh

(http://www.phy.bnl.gov/~xqian/juno_reading/juno_tcshrc)

– Tip:• JUNO software needs CERNLIB, they just downloaded some compiled

cernlib from somewhere, and unpack it. So it may not compatible with your compiler, so you may need to build CERNLIB yourselves, and replace the CERNLIB in the ExternalLibs/CERNLIB

• It is crucial to clean up the global environment. I had this problem as I predefined PYTHONPATH in my global environment

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Running Simulation

• Simulation Example– offline/Simulation/DetSim/DetSim1/share/pyjob.py

• Reconstruction Example– offline/Reconstruction/RecTimeLikeAlg/share/

time_like_rec.py

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Outline• Highlight in background rates estimation

(Liangjian and Chao)• Impact of fine structures in reactor spectrum

(Xin)• Requirement in Energy resolution (Liang)• Installation/Running of JUNO simulation (Xin’s

experience)• Strategy and Plan

22

Current Efforts• US Simulation Efforts:– Jiajie Ling (UIUC), Dawei Liu (UH), Xin Qian (BNL), Chao

Zhang (BNL) – Each person expects 10-20% of their efforts

• Need to focus on certain topics to ensure some useful results:– Initially, we will evaluate the overall calibration plan

• We then will decide on the detailed tasks

– We are also collecting important questions to be addressed (Bob, Kirk, Lianjian etc)

– Wei Tang (BNL) is summarizing the Daya Bay experiences, expect to have some results by next meeting