[clas12_rgk] Range of the scattered electron energies

[burkert]

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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