Re: More on BCAL energy deposition

[Alex Dzierba <dzierba@indiana.edu>]

Yes - I agree - I thought more about it last night and came to the
same conclusion.  And of course your statement about the M.C. is
also correct - assuming that it is being implemented properly --
the "if" is why we do the several percent sanity check.

Cheers
Alex

At 11:24 AM -0400 6/9/07, Richard Jones wrote:
>Alex,
>
>The delay of the shower initiation for gammas is already accounted 
>for in the formula you are using (contains a +/- term for 
>gammas/electrons).  If you do it again, it will double-count.  I 
>really don't think it is worth trying to be this precise with the 
>effective shower profile formula.  It has effective quantities for Z 
>and the critical energy E_c which are only approximations to the 
>much more complex behavior being simulated in the MC.  I would not 
>trust the analytical formula to better than a few percent.  The MC 
>is much more precise because it does the exact integral numerically.
>
>Richard Jones
>
>
>Alex Dzierba wrote:
>>Hi Beni
>>
>>Thanks for your observation and I should of course take the effect into
>>account - I will.  But - it will make things worse because now I consistently
>>underestimate the deposition in layer 1 and overestimate in layer 2
>>(assuming the simulations are correct) and this will be even more the
>>case when I properly distribute the start of the shower into the calorimeter.
>>
>>Cheers
>>Alex
>>
>>
>>At 12:37 PM -0400 6/8/07, beni zihlmann wrote:
>>>Hi Alex,
>>>when you do the analytical calculation you are assuming that the 
>>>shower starts
>>>right at the beginning of layer 1. correct? In the simulation the 
>>>shower will
>>>begin usually inside layer one or even deeper. This might be one 
>>>of the reasons for
>>>the discrepancy.
>>>
>>>cheers,
>>>Beni
>>>
>>>
>>>B. Zihlmann
>>>Indiana University
>>>Physics Department
>>>727 E. Third Street
>>>Bloomington, IN 47405
>>>phone: (812) 855 6973
>>>Fax:   (812) 855-5533
>>
>>
>
>
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-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Alex R. Dzierba
Chancellor's Professor of Physics (Emeritus)
Department of Physics / Indiana U / Bloomington IN 47405 / 812-855-9421
JLab Visiting Fellow
Jefferson Lab / 12000 Jefferson Ave / Newport News, VA 23606 / 757-269-7577
Home Phone: 812-825-4063  Cell:  812-327-1881  Fax: 866-541-1263
http://dustbunny.physics.indiana.edu/~dzierba/
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~