Selection of the elastic events has applied done on the following distributions
  • 175 < delta_phi < 185
  • tanTheta*tanTheta > 1
  • pion and proton identification via cuts on mass
  • ppi- missing mass2 > 1.35

Please note that in comparison to the beam momentum 690MeV/c

we see 30MeV upward shift for the mean value of ppi- invariant mass, as expected from

higher momentum of 748 MeV /c

PPIM_INV_MASS.gif
As for the 690 MeV /c point mean value of CMS is shifted by 20 MeV below expected 1.526 MeV. Most likely due to energy loss of pions and protons in target.

Resolution of CMS reconstruction 1%

Total number of elastic scattering events ~ 5 MLN ,

P_THETA_MOM.gif

PPIM_MOM.gif

PPIM_MISS_MASS2_PT.gif

Overlay of ppi- missing mass^2 from PE (blue line) target and C (red line) one.

Spectra are normalized to yield in the ragio far from the peak position.

PPIM_miss_mass2_C_PE_748_1.gif

Non-elastic events

PPIM_MISS_MASS2_nonEla_PT.gif

Overlay of ppi- missing mass^2 for non-elastic events from PE (blue line) target and C (red line) one.

Spectra are normalized to yield in the ragio far from the peak position.

PPIM_miss_mass2_notElastic_C_PE_748_1.gif

Fit of the ppi- missing mass gives a mean position of the pi0 peak at 2.68e-2 (expected 1.93e-2 ) - it corresponds to 20 MeV too large pi0 mass- and

total number of ppi-pi0 events (after background subtraction) of 0.587 MLN
Topic attachments
I Attachment Action Size Date Who Comment
PIM_THETA_MOM.gifgif PIM_THETA_MOM.gif manage 20.3 K 05 Sep 2014 - 20:27 GosiaSudol pi- theta vs. p
PPIM_INV_MASS.gifgif PPIM_INV_MASS.gif manage 8.9 K 05 Sep 2014 - 21:45 GosiaSudol ppi- invariant mass
PPIM_MISS_MASS2_PT.gifgif PPIM_MISS_MASS2_PT.gif manage 10.0 K 05 Sep 2014 - 20:41 GosiaSudol ppi- elastic events missing mass2 using PionTracker
PPIM_MISS_MASS2_nonEla_PT.gifgif PPIM_MISS_MASS2_nonEla_PT.gif manage 11.4 K 05 Sep 2014 - 20:41 GosiaSudol ppi- non-elastic events missing mass2 using PionTracker
PPIM_MOM.gifgif PPIM_MOM.gif manage 22.6 K 05 Sep 2014 - 20:40 GosiaSudol pi- mom vs. p mom
PPIM_dphi.gifgif PPIM_dphi.gif manage 8.7 K 05 Sep 2014 - 21:37 GosiaSudol ppi- delta phi
PPIM_miss_mass2_C_PE_748.gifgif PPIM_miss_mass2_C_PE_748.gif manage 6.4 K 09 Sep 2014 - 14:00 GosiaSudol p pi+ missing mass2, PE and C target at 748 MeV
PPIM_miss_mass2_C_PE_748_1.gifgif PPIM_miss_mass2_C_PE_748_1.gif manage 6.4 K 09 Sep 2014 - 19:36 GosiaSudol p pi- missing mass2, PE and C target at 800 MeV
PPIM_miss_mass2_notElastic_C_PE_748.gifgif PPIM_miss_mass2_notElastic_C_PE_748.gif manage 7.2 K 09 Sep 2014 - 14:01 GosiaSudol p pi- missing mass2 (non-elastic), PE & C, 748 MeV
PPIM_miss_mass2_notElastic_C_PE_748_1.gifgif PPIM_miss_mass2_notElastic_C_PE_748_1.gif manage 7.1 K 09 Sep 2014 - 19:36 GosiaSudol p pi- missing mass2 (non-elastic), PE & C, 748 MeV
P_THETA_MOM.gifgif P_THETA_MOM.gif manage 20.4 K 05 Sep 2014 - 20:40 GosiaSudol proton theta vs. p
Topic revision: r9 - 09 Sep 2014, GosiaSudol
 
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