Final Cuts for Gen01 Q2=0.5 and Q2=1.0 Data

Cuts for Q2=0.5 Data
based on the definition used for Butcher v541

standard Neutron
   standard Proton
11 <= ntrk_PID <= 15   1 <= ntrk_PID <= 8
theta_pq < 0.11   -
-   ntrk_dx < -0.10
0.26 < hstheta
2.0 < hcer_npe
0.889 GeV < W < 0.989 GeV
2.0021 GeV < Eprime
12.0 < ntrk_E
-3.0 ns < ntrk_t < 5.0 ns
-40. cm < ypos < 40. cm
-

  Cuts for Q2=1.0 Data
based on the definition used for Butcher v1044

standard Neutron
   standard Proton
11 <= ntrk_PID <= 15   1 <= ntrk_PID <= 8
theta_pq < 0.08   -
-
0.26 < hstheta
2.0 < hcer_npe
0.869 GeV < W < 1.009 GeV
2.829 GeV < Eprime
12.0 < ntrk_E
-3.0 ns < ntrk_t < 5.0 ns
-40. cm < ypos < 40. cm
-3.2 cm < hszbeam < 3.2 cm

 

The variable names above are the actual names used in the coincidence Ntuple, except those in italics; these latter ones are derived as follows:
ypos horizontal intercept of the track with plane 3; determined by multiplying the horizontal slope ntrk_dy with the nominal z-position of plane 3 (429.1cm for Q2=0.5, 620.1cm for Q2=1.0)
Eprime kinetic energy of scattered electron, EXCLUDING any radiative Eloss corrections. Obtained from reconstructed track delta (hsdelta) by applying the nominal central momentum via:

hpcentral * (1+hsdelta/100.)

Some replay iterations additionally used a 0.9967 scale factor, originating from a -0.33% offset correction between nominal and actual HMS momentum (due to the magnet program), which has been found to not apply (saturation effect?). The actual hpcentral values are:

run no
 hpcentral
 hpcentral*0.9967
1-40001 0. 0.
40002-40135 2.648 2.639
40136-40138 1.790 1.784
40139-40513 2.060 2.053
40514-40629 2.004 1.997
40630-41791 1.9627 1.956
41792- 2.810 2.801
The final results (4th pass) do not include the -0.33% offset.
(frw) 7-2003