[clas12_rgk] Range of the scattered electron energies

[Francois-Xavier Girod]

A couple notes now that the momentum threshold for electron is back to 1.5
GeV
PCAL+ECAL > 300 MeV is the threshold for 1.5 GeV/c electrons. The
corresponding value for PCAL is 170 MeV

In addition, 1.5 GeV/c momentum has a large polar angular range outside of
acceptance for inbending torus full field (below 17 degrees or so depending
on phi_sector)

On Fri, Nov 9, 2018 at 3:28 PM Valery Kubarovsky <vpk at jlab.org> wrote:

> 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> <burkert at jlab.org>
> *To: *"Valery Kubarovsky" <vpk at jlab.org> <vpk at jlab.org>, "Viktor Mokeev"
> <mokeev at jlab.org> <mokeev at jlab.org>
> *Cc: *"clas12 rgk" <clas12_rgk at jlab.org> <clas12_rgk at jlab.org>, "annalisa
> dangelo" <annalisa.dangelo at roma2.infn.it> <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> <mokeev at jlab.org>
> *To: *"clas12 rgk" <clas12_rgk at jlab.org> <clas12_rgk at jlab.org>
> *Cc: *"Volker Burkert" <burkert at jlab.org> <burkert at jlab.org>, "annalisa
> dangelo" <annalisa.dangelo at roma2.infn.it> <annalisa.dangelo at roma2.infn.it>,
> "Valery Kubarovsky" <vpk at jlab.org> <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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>
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