[G14_run] Test on the eloss package

[daoh at andrew.cmu.edu]

Dear all,

I updated the link below to show you my eloss study for ppim reaction.
This time I have "cleaned up" most of PID background.

http://www-meg.phys.cmu.edu/~dho/eloss_study_ppim_gold2.html

Sincerely,
Dao Ho





> Haiyun et al,
>
> 	Using 500 MeV/c as a benchmark, Eugene's program gives energy losses of
> 10.0 MeV for protons and 1.5 MeV for pions.  How thick does this imply
> the target material is?
>                    protons        pions
> all plastic       1.6  cm        0.76 cm
> all aluminum      0.74 cm        0.22 cm
>
> This shows that the program is internally inconsistent for what it
> returns for pions and protons at a given momentum.  But also, the
> material thickness the numbers imply seems like a lot:  is the HDIce
> target at 90 degree really the equivalent of 1.6cm of plastic or .74cm
> of aluminum?  That seems very thick.
>
> Reinhard
>
> ___________________________________________________________________
> Reinhard Schumacher         Department of Physics, 5000 Forbes Ave.
> Carnegie Mellon University, Pittsburgh, PA 15213, U.S.A.
> phone: 412-268-5177         web: www-meg.phys.cmu.edu/~schumach
> ___________________________________________________________________
>
> On 04/09/2014 10:37 PM, Dr. A.M. Sandorfi wrote:
>> Thanks Haiyun,
>> This provides a direct comparison with my earlier direct calculation,
>> tracking the Eloss through sequential layers.
>>
>> For protons:
>> - 65 MeV kinetic energy corresponds to 355 MeV/c momentum, for which
>> your
>> Eloss plot gives 22 MeV for delta_E. It should be 27 MeV.
>> - at the upper end of your plot, 1000 MeV/c, or 433 MeV kinetic energy,
>> the
>> delta_E seems to be a little under 4 MeV. This is closer, but still too
>> low.
>> The delta_E shouldn't be less than 5.
>>
>> Still the pion Eloss seems to be off the most.
>> Andy
>>
>>
>>
>>
>>
>>
>> On 4/9/14, 6:08 PM, "Reinhard Schumacher"<schumacher at cmu.edu>  wrote:
>>
>>> Hello Haiyun,
>>>
>>> Nice work.  Your proton band looks like it gives higher energy loss for
>>> protons at a given momentum than Dao's and the others'.  At 300 MeV/c,
>>> your plot shows ~30 MeV energy loss, while Dao's shows ~10 MeV.  For
>>> pions the behavior is less clear: both your calculation and his give
>>> less than 2 MeV energy loss at 300 MeV/c, which is very likely too
>>> small.  So this leads to the questions:
>>>
>>> 1) Why do you get higher, probably closer to correct, energy losses for
>>> protons?
>>>
>>> 2) Why does the program give unrealistically small energy losses for
>>> everybody?
>>>
>>> Reinhard
>>>
>>> ___________________________________________________________________
>>> Reinhard Schumacher         Department of Physics, 5000 Forbes Ave.
>>> Carnegie Mellon University, Pittsburgh, PA 15213, U.S.A.
>>> phone: 412-268-5177         web: www-meg.phys.cmu.edu/~schumach
>>> ___________________________________________________________________
>>>
>>> On 04/09/2014 05:16 PM, Haiyun Lu wrote:
>>>> Dear g14ers,
>>>>
>>>> I did a straight test on the eloss package of g14. I made up some
>>>> events
>>>> of proton and pi-. They are at fixed vertex position at (0,0,-7.5),
>>>> which is the center of the target. They are at the fix polar angle, 90
>>>> degree, which is perpendicular to the beam line. The azimuthal angle
>>>> and
>>>> the momentum are variable. Then I plot the energy loss versus the
>>>> momentum for proton and pi-. I attached a file "eloss_test.png". There
>>>> are two bands in the histogram. The upper one is for proton and the
>>>> lower one is for pi-.
>>>>
>>>> Best regards,
>>>> Haiyun
>>>>
>>>>
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>>
>>
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