MuCAP Analysis Meeting

@ Berkeley


Feb. 27 - Mar.1 ,  2006



Tentative  Agenda of the Meeting


Short Summary :

The very important conclusion of this meeting is, that we do not have a mysterious, unknown  'gondola effect' , but we have identified two mechanisms that can produce lifetime variations across individual gondolas:
- one which is due to decay electrons observed in the TPC (see Steve's talk), relevant for the clean fill data and mu+ data,  and
- one is caused by mu_d diffusion and scattering (see Tom's talks), pronounced visible in the natural hydrogen data.
We now do understand qualitatively these effects, and further understanding of a good MuStop definition should eliminate the observed gondola lifetime variation in the clean fill data. Tom's fast Monte-Carlo using better scattering modeling by real data input together with Brendan's diffusion data should give us also a quantitative reproduction on the mu_d diffusion caused lifetime variation in the natural hydrogen data.
Tom and Steve have to further work on comparing and refining their good mu-stop definition, as the difference between the two analysis are now,  with Steve's new version only very small, and therefore we would like to understand why Tom still sees a little larger effect. A firsts check by event comparison showed, that Steve actually rejects only a few more noise hits due to a sllightly different pile-up definiton. Steve also has a slightly different fiducial volume cut and allows only single pixel gaps in a muon "track" while TOm allows 2.
Fred also showed that in a new production pass, the lifetime variation observed in the Run8 mu+ run, the nitrogen and the deuterium doped runs, is gone.
Fred's new higher statistics simulation of the effect due to beating between the beam RF and the CAEN clock interpolator showed, that there might be a relevant effect on the 15 ppm level. However, this effect depends on the exact frequency diffrence and therefore should be finally determined after our Run8 clock will have been unblinded.
Tom explained his note on muon detector inefficiencies and explained his result that if we can start lifetime fits at early times, there should anly be a negligible effect to our result. Peter explained his thought about muon detector inefficiencies in probability space and pointed out that Tom's treatment neglects the term due to two overlapping muon tracks in the TPC.  Tom thought that this term is negligible. Peter also pointed out that we can measure the muon detector inefficiencies by artificially increasing the pileup rate, that is by killing an observed muSC/muPC pileup signal in our data and determine the caused effect on the lifetime. The same check with data can be done by artificially increasing the deadtime of the muon beam counters.
Bernhard showed his conclusions on the impurity data from the last Runs. He clearly pointed out the importance of the humidity sensor and the measurement at 2 different flow rates which give us the only handle on our moisture problem.  Clearly there is the necessity of re-doing the measurement with CHUPS at 2 different flow rates and wait for a long enought time till the moisture level is equilibrated. The problem that our observed yields cannot interpreted with published rates was discussed and a possible solution via an effective transfer rate pointed out.

As result of the meeting, we have set up a priorotized task list, given below, which will guide Steve and Tom in the next monthes.




Collected Talks and Comments


Run 8     A N A L Y S I S


Steve Clayton              Recent Analysis Results - the gondola effect dissolved by a new Muon stop definition  (ppt,  pdf)

Bernhard Lauss          Monte-Carlo for Probability of Elow hits = Electron energy distribution in TPC (ppt)

Tom Banks                  Recent Results - a fast Monte-Carlo for understanding the gondola effect caused by scattering and diffusion (pdf)

Peter Kammel              Data based estimate of diffusion driven gondola effect (ppt)

Tom Banks                   Berkeley Specific Analysis Concerns (pdf)

Fred Gray                    update on his results of the gondola effect in mu+, N2 doped protium. and natural hydrogen (pdf)

Fred Gray                    Analysis of the Run9 AK3 data (pdf) comments (pdf)

Tom Banks                  Muon Detector Inefficiencies (pdf)   -  Note on muon detector inefficiencies

Peter Kammel             Thoughts on Muon detector inefficiencies (ppt)

Bernhard Lauss          High  impurities in MuCAP - Run7/8/9 - (ppt)   Note on High-Z impurities in MuCAP

Fred Gray                    RF systematics (pdf)

Steve Clayton              lambda_OP and lambda_ppmu effect in MuCAP (pdf1, pdf2)

Tom Banks                  Deuterium Correction (pdf)

Fred Gray                    Error Propagation for Deuterium Correction (pdf)

Dave Hertzog / Bernhard Lauss /Discussion   Roadmap to a first MuCAP publication (ppt)


Tom Banks     prioritized remaining tasklist for the Run 8 analysis efforts  http://kaon.physics.berkeley.edu:8080/analysis-run8/56

                        tentative timeline for the remaining Run 8 analysis issues   http://kaon.physics.berkeley.edu:8080/analysis-run8/57




RUN 10          Preparation

Brendan Kiburg         Run 9  Analysis (ppt)

Brendan Kiburg         Run 10 Preparation Tasks (ppt)

Peter Kammel             PSI Schedule for 2006 (pdf)

Peter Winter               Task list for Run 10 preparation  (discussion notes)


Pictures:

Here are a few fotos.



Participants:

University of Illinois at Urbana-Champaign
Steve Clayton, David Hertzog, Peter Kammel, Brendan Kiburg, Peter Winter

UC Berkeley
Tom Banks, Tom Case, Ken Crowe, Stuart Freedman, Fred Gray, Bernhard Lauss