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Re: Gondola effect et al 217-265-9888 Tel conf Tuesday usual time

Dear friends,

here are a few pre-comments to todays Teleconf. from our side:

- Freds decay-rate plot indeed suggests that the problem may be
   caused by how the muon stop is defined in the tpc.

- it is possible that decay electrons going approx. parallel
   to the anode wire can make some E_low signals. If such
   signals could cause the stop to be rejected then early decay
   events might get lost which would flatten the exponential.

   However we cannot understand why (in the case of mu+) there is
   such a sharp effect restricted to one gondola only (4 and 12),
   we would rather expect a distribution as seen with mu-.

- Steves figure showing the very strong decay rate dependence
   from Tstart seems to indicate clearly that we have a huge
   problem in the first 2 microseconds (at least). Obviously
   one cannot believe any fit result until we get such dependences
   under control.

- our suggestion to the analysis crew is to investigate (and vary)
   the muon stop definition and check its effect on gondola fits
   and the Tstart dependence.

We are looking foreward to hearing you soon

Malte and Claude


Peter Kammel wrote:

> Dear Fred,
> 
> Thanks for the interesting analysis. We are looking forward to
> tomorrow's telconf. One thought conc the mu-e correlation. An additional
> source of correlation could be the rejection of muon tracks with
> forward going green points after the blue mu stop point. If the forward
> going green points are generated by decay electrons depositing
> most of their energy on one cathode, they might kill the muon.
> 
> Best regards
> 
> Peter
> 
> 
> 
> 
> On Mon, 15 Aug 2005, Frederick Gray wrote:
> 
>> Dear muCappers,
>>
>> You are cordially invited to have a look at this page:
>>  http://kaon.physics.berkeley.edu/~fegray/mucap/teleconf-2005-08-16/
>> which I hope we will be able to talk about at tomorrow's teleconference.
>>
>> It describes the mechanism that we have been discussing in Berkeley to
>> explain the "gondola effect" (i.e. the phi-dependence of the fitted
>> lifetime).  In particular, if Claude and Malte are not away on 
>> holidays, we
>> would welcome comments from them as TPC experts.
>>
>> Thanks very much,
>>
>> -- Fred
>>