[clas12_rgk] 2 pion cuts

[Viktor Mokeev]

FX,

 In my opinion, the answer is no. The question is what size will be acceptable.

   Best Regards,
                                Victor
________________________________
From: clas12_rgk <clas12_rgk-bounces at jlab.org> on behalf of Francois-Xavier Girod <fxgirod at jlab.org>
Sent: Wednesday, June 17, 2020 1:49 PM
To: Volker Burkert <burkert at jlab.org>
Cc: clas12_rgk at jlab.org <clas12_rgk at jlab.org>
Subject: Re: [clas12_rgk] 2 pion cuts

Dear all

>From what I had understood the goal of the double pion analysis, ultimately, is to measure a cross section. Are we sure that a blanket veto on “no other hadron” is safe for cross sections?

Best regards
FX

On Wed, Jun 17, 2020 at 7:41 PM burkert <burkert at jlab.org<mailto:burkert at jlab.org>> wrote:
Evgeny,
Maybe I don't understand the nomenclature. But it appears that

- In first cut you ask for presence of (2pi+ and no other hadrons), and
in the MM2 (e, pi+, pi-), where do you get the pi- from?

- in second cut you ask for presence of (p, 2pi+ and no other hadrons)
and in MM2 you ask for presence of p,pi+,pi-). Again, where is the pi-
from?

Volker



On 6/17/20 1:30 PM, golovach at jlab.org<mailto:golovach at jlab.org> wrote:
> Dear Volker,
>
> I do no see the typos
> the first arrow ---> pi+, pi+ are present
> the second arrow ----> p, pi+, pi+ are present
> That is correct.
>    Evgeny
>
>
>> Evgeny,
>>
>> Is seems to me there are two typos in your selection (marked by arrow
>> --->:)
>>
>>
>> On 6/17/20 12:19 PM, golovach at jlab.org<mailto:golovach at jlab.org> wrote:
>>> Hi Nick,
>>>
>>> MM2 cuts for the 2 pion events are:
>>> The presence of extra electrons and neutrals are not taken into account.
>>> if p, pi+   are present and there are no other hadrons,
>>>     then  MM2(e_prot_pip)>-0.35 && MM2_e_prot_pip<0.35
>>> if p, pi-   are present and there are no other hadrons,
>>>     then  MM2(e_prot_pim)>-0.35 && MM2_e_prot_pim<0.35
>>> ---> if pi+, pi+ are present and there are no other hadrons,
>>>     then  MM2(e_pip_pim)> 0.62 && MM2_e_pip_pim<1.18
>> should that be: if pi+, pi- are present ......
>>
>>> ----> if p, pi+, pi+ are present and there are no other hadrons,
>>>     then  MM2(e_prot_pip_pim)> -0.018 && MM2_e_prot_pip_pim<0.018
>> should that be: if  p, pi+, pi- are present,,
>>
>>
>> Volker
>>
>>
>>> Could you, produce train15 (say for the run 5898) for the test?
>>>
>>>
>>> I do not understand one thing.
>>> Annalisa has shown that the train eTwoChargedH takes 17% of the total
>>> size.
>>>
>>> I have analyzed a subset of the dst files in
>>> /lustre19/expphy/volatile/clas12/rg-k/production/pass0/v1_1.1.12/dst/recon/005898/
>>> and I see much larger reduction of the number of the 2 pion events.
>>> If I select 2 pion events I have only ~2% of the total number of events.
>>> If I select 2 pion events and apply MM2 cuts I have ~0.88% of the total
>>> number of events.
>>> May be the MM2 cuts are not necessary?
>>>
>>> My selection of the 2 pion events as I mentioned is:
>>>     The presence of extra electrons and neutrals are not taken into
>>> account.
>>>     p, pi+   are present and there are no other hadrons
>>>     p, pi-   are present and there are no other hadrons
>>>     pi+, pi+ are present and there are no other hadrons
>>>     p, pi+, pi+ are present and there are no other hadrons
>>>
>>>     Evgeny
>>>
>>>
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>>
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