the summery of the nemo 3 meeting. the topic discussed 1) some problems in variation of the gain of...

The Summery of the NEMO 3 meeting

The topic Discussed1) Some problems in variation of the gain of the counters and resoulution of the counters (for PMTs). This can be taken in toaccount in the analysis. But Roger Arnold belives that this variationleads to a amall effect on the results -> So at the end everybody decided to ignore this for the future publications! (Nd150 for Example).

2) PM timing, Laser Time Correction (LTC) and purpose of doing it!For laser runs for each PM from trigger statement

TDC*k+T(ADC) + TOF(laser light) +TS = const

Where TDC is the mean digital value of TDC in channels, K the TDC channel constont (0.053 ns/ch). T(ADC) time correction which depend on ADC content

LTC PMiLaserRunj = TDC+T(ADC) PMi

LaserRunj - TDC+T(ADC) PMiReferenceRun

Which reference Run #1404!!

Problem Add Status of PM

There is no TS +1000

There is no T(ADC) +2000

There is no LTC +1000000

Bad PM between two laser runs +2000000

Kill event if it have the above condisions!As this information is just avaible for good runsI should not use run number with status!=1 which I showed the result on Jaca meeting.

The Conclusion for me!!!

3) A discussion opened by Victor that electron energy comingfrom Bi207 data (from the calibration runs) has a higer peaks thanthe simulated MC! And he predicted 5% uncertainty on MC Simulation.

This means I need to consider this in my Bi207 activity measurement until this problem is going to be fixed!

4) External background (one of the main discussion topics and still not sure!), can be estimated with two methods.

One is to look at eg-external channel and one crossing electron Channel.

Background model like for the low radon period (best fit!!)

Despite Victor’s efford to underestand why the external background is not described and lots of simulations, could not find the source of the missing backgrounds in low energy crossingelectrons!!!

Again more or less the same is seen by G.Broudin.

The second method is described by V.Vassiliev (maybe less precise but answeres very well!

The external background is coming from g-sources from outsidethe detector, so need to know spectrum of g quanta near sourceFoil! He looks at 2electron channel instead of eg-ext and crossingelectron! model spectrum= 208Tl + 228Ac + 214BI + 214Pb + 40K + 60CoHe estimates the coefficients from eg -ext channel analysis!

How it mimic events?

External

double Compton Compton + Moller pair production

dominant mode

Results of the fit (see the note)external wall, Phase II data Internal wall

petal

Still not sure which approach to use for the purpose of Publications, but Vladimir’s method seem to be a solution Fro low external background isotopes (Ca48 and Nd150..)

The discussion is going to be continued …..!

5) Radon measurement inside the tracker! More agreementIn this part! Thy try to estimate the background by lookingat alpha-channel analysis (e-alpha,ega,..). 11.5% uncertaintyon the measurement which can be improved with direct calibration of Bi214 source!

6) List of the results that need to be extracted!

LIST OF RESULTS WHICH HAVE TO BE EXTRACTED FROM THE DATA

1. 2-decay to the ground state.Finally we have to present: a) 2e spectrum; b) single e spectrum; c) angular distribution. d) half-life value (T1/2); with statistical and systematic errors. 2. 0-decay.

a) decay to the ground state (lim T1/2; <m>, RHC); b) decay to the 2+

1 excited state (lim T1/2); c) decay to the 0+

1 excited state (lim T1/2).

3. 00-decay.

As minimum:

1) limit (T1/2) on “ordinary” decay with n=1.

But it is better to add limits on other possible schemes with n = 2, 3, 7. (See our NEMO-2 and NEMO-3 results: Nucl.Phys. A 678 (2000) 341; Nucl. Phys. A 781 (2007) 209.)

4. Finally we will extract values or limits for NME(2), <m>, <>, <>, <gee>, ’111 and so on.

THEN IN EACH INDIVIDUAL CASE THEY WILL DECIDE WHICH VALUES WE HAVE TO PUBLISH AND IN WHICH WAY.