[clas12_rgk] Range of the scattered electron energies

[Valery Kubarovsky]

Volker, 
I agree with any trigger limits that will satisfy the spokespersons of the experiment. 
I just want to know the parameters to start with. That's it. 
Personally I prefer to go to as high to W as possible. 
regards, 
Valery 

> From: "Volker Burkert" <burkert at jlab.org>
> To: "Valery Kubarovsky" <vpk at jlab.org>
> Cc: "Viktor Mokeev" <mokeev at jlab.org>, "clas12 rgk" <clas12_rgk at jlab.org>,
> "annalisa dangelo" <annalisa.dangelo at roma2.infn.it>
> Sent: Friday, November 9, 2018 3:13:00 PM
> Subject: Re: Range of the scattered electron energies

> Valery,

> The 2.5 GeV threshoild came out of the blue during that meeting, In the proposal
> we discuss surveys going to much higher mass. It would not be justified to
> lower the proposal requirements.

> Here is an excerpt of the abstract in the proposal for hybrid baryons:

> "The experiment will use longitudinally polarized electron beams of 6.6 GeV and
> 8.8 GeV to
> cover the range of invariant mass W up to 3 GeV and Q2 from 0.05 GeV2 to 2
> GeV2."

> Please lets not mess with the goals of the proposal.

> Volker

> to On 11/9/18 2:05 PM, Valery Kubarovsky wrote:

>> Hi All:

>> E' energy threshold suggested:

>> Victor 3.54 GeV - exact energy limit
>> Volker 2.00 GeV - includes correction for the resonance's widths.

>> I think that the 2 GeV correction is too much for the resonance's widths.
>> I suggest to have more realistic estimations. If trigger rate will permit we can
>> always lower the calorimeter energy cut. I don't think that it will be the case
>> and we will decide any way what to do: make a stronger trigger cuts or go down
>> with the beam current. Let us establish the trigger limits that is absolutely
>> necessary. Later on we can adjust it.
>> Regards,
>> Valery

>>> From: "Volker Burkert" <burkert at jlab.org>
>>> To: "Valery Kubarovsky" <vpk at jlab.org> , "Viktor Mokeev" <mokeev at jlab.org>
>>> Cc: "clas12 rgk" <clas12_rgk at jlab.org> , "annalisa dangelo"
>>> <annalisa.dangelo at roma2.infn.it>
>>> Sent: Friday, November 9, 2018 11:51:55 AM
>>> Subject: Re: Range of the scattered electron energies

>>> I think Victor calculated a sharp threshold without considering the resonances
>>> have broad widths for hybrids.

>>> I suggest the following, i.e. W thresholds are above 3 GeV in either case.

>>> 7.5 GeV: E'min>2.0 GeV
>>> 6.5 GeV: E'min>2.0 GeV

>>> For the upper E' I suggest to lower the numbers so that resonance width are
>>> taken into account.
>>> 7.5GeV: E'max< 7.0 GeV
>>> 6.5GeV: E'max < 6.0 GeV

>>> Thresholds may have to be adjusted for energy leakage.

>>> Volker

>>> On 11/9/18 11:16 AM, Valery Kubarovsky wrote:

>>>> Hi All:

>>>> The scattered electron energy in the mail below differs by a factor of 4 from
>>>> the table that was presented today (see attached screenshot). I believe that we
>>>> have to define the trigger parameters more precisely.

>>>> Regards,
>>>> Valery

>>>>> From: "Viktor Mokeev" <mokeev at jlab.org>
>>>>> To: "clas12 rgk" <clas12_rgk at jlab.org>
>>>>> Cc: "Volker Burkert" <burkert at jlab.org> , "annalisa dangelo"
>>>>> <annalisa.dangelo at roma2.infn.it> , "Valery Kubarovsky" <vpk at jlab.org>
>>>>> Sent: Friday, November 9, 2018 10:22:06 AM
>>>>> Subject: Range of the scattered electron energies

>>>>> Dear Colleagues,

>>>>> I computed the range of the scattered electron energies for Q^2=0 and at the W
>>>>> interval from 1.5 GeV (W_min) to 2.5 GeV (W_max), which is the range of our
>>>>> physics interest.

>>>>> For the beam energy of 7.5 GeV the energy range of the scattered electrons
>>>>> should be from 4.64 GeV to 6.78 GeV.
>>>>> For the beam energy of 6.4 GeV the energy range of the scattered electrons
>>>>> should be from 3.54 GeV to 5.67 GeV.

>>>>> The details of the evaluations are in the attached file.

>>>>> Best Regards,
>>>>> Victor

>>>>> PS For Q^2>0.1 GeV^2 the actual value of Q^2 becomes comparable with the \nu in
>>>>> the attached file and, therefore, should be taken into account. In comparison
>>>>> with the photon point, actual Q^2 value should increase \nu and decrease the
>>>>> range of the scattered electron energies.
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