[clas12_rgk] [Clas12_first_exp] trigger efficiency vs ECal treshold
burkert
burkert at jlab.org
Wed Dec 12 21:58:53 EST 2018
I believe the roads were taken out as they had only minimal effect (3%
or so) for outbending electrons in improving trigger purity.
Volker
On 12/12/18 7:58 PM, Francois-Xavier Girod wrote:
> I believed we are using the DC roads
> If we are not then my question is moot
>
> On Wed, Dec 12, 2018 at 7:56 PM Stepan Stepanyan <stepanya at jlab.org
> <mailto:stepanya at jlab.org>> wrote:
>
> I am sure you can, but you should ask Andrea.
>
> Are we using roads or segment now.
>
> Stepan
>
>> On Dec 12, 2018, at 7:46 PM, Francois-Xavier Girod
>> <fxgirod at jlab.org <mailto:fxgirod at jlab.org>> wrote:
>>
>> Dear Stepan
>>
>> Yes, this is what I am asking for: can we please have the plot
>> showing the DC roads efficiency vs momentum?
>> I only need this material for discussion of my earlier proposal
>>
>> Best regards
>> FX
>>
>> On Wed, Dec 12, 2018 at 7:42 PM Stepan Stepanyan
>> <stepanya at jlab.org <mailto:stepanya at jlab.org>> wrote:
>>
>> FX,
>>
>> Can you please clarify what you are exactly asking. The DC
>> roads or segments in the trigger have nothing to do with
>> trigger efficiency dependance on ECal trigger threshold. If
>> you worry about efficiency of DC segments or roads for low
>> momentum (~1 GeV) electrons or tracks, Andrea did that
>> studies and as far I remember trigger had almost 100% efficiency.
>>
>> Stepan
>>
>>> On Dec 12, 2018, at 7:35 PM, Francois-Xavier Girod
>>> <fxgirod at jlab.org <mailto:fxgirod at jlab.org>> wrote:
>>>
>>> Thank you Rafo, this is really helpful
>>> I remember we did have a separate validation of the DC
>>> roads. Do you have this documented? I think this included
>>> both simulations and data, but I don't remember the momentum
>>> range. I think the DC roads can validated at low momentum
>>> even with a 300 MeV threshold.
>>>
>>> On Wed, Dec 12, 2018 at 7:30 PM Rafayel Paremuzyan
>>> <rafopar at jlab.org <mailto:rafopar at jlab.org>> wrote:
>>>
>>> Dear Fx, all,
>>>
>>> I looked back one of old presentations, and see that
>>> with 2.2 GeV run that we have in Jan 2018, the ESum
>>> threshold was 150 MeV
>>> https://docs.google.com/presentation/d/1OZ_BDsYiH6t8Mo_D_o9QPIoSQLKkvs7ckKwGx_u9vOs/edit?usp=sharing
>>> Please look into slide 11, the sharp fall of the trigger
>>> is below P < 1 GeV.
>>>
>>> This is not exactly the same this trigger, but
>>> difference is minor, i.e. DC segments are added, then dc
>>> roads, and
>>> because of it some time constants were shifted. This
>>> gives good confidence that the current trigger is also
>>> efficient (99%+) above 1 GeV,
>>> however, if you would like exactly this trigger to be
>>> validated 1ith ESum > 150 MeV, we can take another
>>> random run (about 2 hours g/ good beam),
>>> and check it.
>>>
>>> Rafo
>>>
>>>
>>> On 12/12/18 7:05 PM, Viktor Mokeev wrote:
>>>> Thank you FX for the comment!
>>>>
>>>> Extension of W-coverage may be also beneficial
>>>> increasing chances to explore the hybrid baryon spectrum.
>>>>
>>>> Best Regards,
>>>> Victor
>>>>
>>>> ------------------------------------------------------------------------
>>>> *From:* Francois-Xavier Girod <fxgirod at jlab.org>
>>>> <mailto:fxgirod at jlab.org>
>>>> *Sent:* Wednesday, December 12, 2018 7:00:36 PM
>>>> *To:* Viktor Mokeev
>>>> *Cc:* clas12 rgk; clas12 first exp; Rafayel Paremuzyan
>>>> *Subject:* Re: [clas12_rgk] trigger efficiency vs ECal
>>>> treshold
>>>> Dear Viktor
>>>>
>>>> Thanks for the feedback. Although hybrid baryon is not
>>>> interested in the high W region, lowering the trigger
>>>> threshold for hybrid baryon would only impact the
>>>> experiment in terms of luminosity. The lower W / larger
>>>> momentum region would still be in the trigger, and
>>>> hybrid baryon could benefit from cross-checking their
>>>> cross-sections at different luminosity.
>>>>
>>>> Best regards
>>>> FX
>>>>
>>>> On Wed, Dec 12, 2018 at 6:26 PM Viktor Mokeev
>>>> <mokeev at jlab.org <mailto:mokeev at jlab.org>> wrote:
>>>>
>>>> Dear All,
>>>>
>>>> From FX trigger efficiency plot, I see efficiency
>>>> problems at the lab. energies of the scattered
>>>> electron <2.0 GeV or for \nu value above 5.5 GeV
>>>> for the electron beam energy 7.5 GeV. It
>>>> corresponds to the following W ranges where we have
>>>> the problem with trigger efficiency:
>>>>
>>>> Q^2=2.0 GeV^2 W>3.0 GeV
>>>> Q^2=5.0 GeV^2 W>2.5 GeV
>>>>
>>>> For hybrid baryon search, we have no any problem
>>>> with the trigger efficiency at Q^2<2.0 GeV^2 since
>>>> the lightest hybrids are expected in the mass range
>>>> <2.5 GeV. Furthermore, the initial search for
>>>> hybrid baryons will be carried out at Q^2<2.0 GeV^2.
>>>>
>>>> Best Regards,
>>>> Victor
>>>>
>>>> ------------------------------------------------------------------------
>>>> *From:* Francois-Xavier Girod <fxgirod at jlab.org
>>>> <mailto:fxgirod at jlab.org>>
>>>> *Sent:* Wednesday, December 12, 2018 6:09:53 PM
>>>> *To:* Viktor Mokeev
>>>> *Cc:* clas12 rgk; clas12 first exp; Rafayel Paremuzyan
>>>> *Subject:* Re: [clas12_rgk] trigger efficiency vs
>>>> ECal treshold
>>>> Dear Viktor
>>>>
>>>> Rafo can confirmed as he produced the plot, my
>>>> understanding is that the electron momentum is
>>>> measured by the drift chambers
>>>>
>>>> Best regards
>>>> FX
>>>>
>>>> On Wed, Dec 12, 2018 at 6:08 PM Viktor Mokeev
>>>> <mokeev at jlab.org <mailto:mokeev at jlab.org>> wrote:
>>>>
>>>> Dear FX,
>>>>
>>>> Just to make sure, whether P on your plots is
>>>> the energy=momentum of the scattered electron?
>>>>
>>>> Best Regards,
>>>> Victor
>>>> ------------------------------------------------------------------------
>>>> *From:* clas12_rgk <clas12_rgk-bounces at jlab.org
>>>> <mailto:clas12_rgk-bounces at jlab.org>> on behalf
>>>> of Francois-Xavier Girod <fxgirod at jlab.org
>>>> <mailto:fxgirod at jlab.org>>
>>>> *Sent:* Wednesday, December 12, 2018 5:58:01 PM
>>>> *To:* clas12 rgk; clas12_first_exp at jlab.org
>>>> <mailto:clas12_first_exp at jlab.org>
>>>> *Cc:* Rafayel Paremuzyan
>>>> *Subject:* [clas12_rgk] trigger efficiency vs
>>>> ECal treshold
>>>> Dear all
>>>>
>>>> During today's meeting I attempted to have a
>>>> discussion on the trigger efficiency as
>>>> function of ECal threshold. Contradicting
>>>> statements were made during the meeting, so I
>>>> want this discussion to be on record here.
>>>>
>>>> Please see the plot
>>>>
>>>> https://www.jlab.org/Hall-B/secure/clas12/rec_mon/P_Good_emWithEC_5786.png
>>>>
>>>> from Rafo's study of the trigger efficiency. He
>>>> analyzed run 5786 which was taken with the
>>>> random trigger.
>>>>
>>>> - in blue all "good electrons" with Nphe>2,
>>>> E_PCal > 60 MeV, sampling fraction > 0.2 and
>>>> fiducial cuts
>>>>
>>>> - in orange, the electrons satisfy in addition
>>>> E_ECal > 300 MeV
>>>>
>>>> - in red, the events for which the orange set
>>>> was missing the electron trigger bit
>>>>
>>>> The trigger efficiency is defined as (orange -
>>>> red) / orange
>>>>
>>>> https://www.jlab.org/Hall-B/secure/clas12/rec_mon/Eff_All_Good_em_trg_threshold_5786.png
>>>>
>>>> The trigger efficiency below 2 GeV drops
>>>> rapidly, and measuring a cross section in this
>>>> region is challenging
>>>>
>>>> My question during the meeting was: do we
>>>> already have data to show the trigger
>>>> efficiency when the threshold is 150 MeV. My
>>>> understanding is that we do not have this data
>>>> and that to answer this question we need to
>>>> take another random trigger run with the lower
>>>> threshold.
>>>>
>>>> What I have in mind is the following: I agree
>>>> that the bulk of the RG-K data taking can take
>>>> place at 300 MeV ECal trigger threshold and
>>>> highest possible luminosity, but I would like
>>>> to consider the possibility to take a few days
>>>> at a lower trigger threshold to extend the
>>>> cross section measurement to higher W. Again my
>>>> purpose is to minimize the final systematic
>>>> uncertainties.
>>>>
>>>> Best regards
>>>> FX
>>>>
>>>
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>>
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