[G8b_run] Photon Corrections (taggerSag)

[Eugene Pasyuk]

Guys, whys is it E0=4.55?
According to the calibration database it is 4558.94 MeV (4.559 GeV)
It is 9 MeV difference.

-Eugene

Charles Hanretty wrote:
> Hello all,
>       Below is the C++ translation from the Fortran code that Mike wrote to 
> correct the photon energies.
> 
>    float E0 = 4.55;
>    double egdivE0;
>    egdivE0 = pho_energy/E0 + 0.00134;
> 
>    if (egdivE0 < 0.401) {
>      egdivE0 = egdivE0 - 0.00599597 + 0.0390912*egdivE0 -
> 0.0573218*egdivE0*egdivE0;
>    }
>    if ((egdivE0 >= 0.401) && (egdivE0 <= 0.674)) {
>           egdivE0 = egdivE0 - 0.0181293 + 0.0675599*egdivE0 - 
> 0.0541268*egdivE0*egdivE0;
>    }
>    if (egdivE0 > 0.674) {
>           egdivE0 = egdivE0 - 0.0511162 + 0.138208*egdivE0 - 
> 0.0867757*egdivE0*egdivE0;
>    }
> 
>    pho_energy = egdivE0*E0 + pho_energy*(-0.0035);
> 
> Where "pho_energy" is the energy of the photon as taken from the data 
> file and "E0" is the (e-)beam energy.
> 
>     A CLAS-note for the g8b Tagger Sag study is almost finished.
> 
> -Chuck
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