I think I should be able to accomodate all this by next week's
meeting.
I can answer these three right now.
> a) What exact W-cut are you using for the profile histograms?
abs(W-0.94)<0.04
> b) Did you use the same W-cut for the real data in
> New_BeamEnergy.pdf?
No... I used much more cuts for the real data.
e.g. EP_elas_tight_eL||EP_elas_tight_eR
> e) Are the wiggles in the angular distributions also present
> in the data?
Yes. These are the wiggles that Chris sees after his attempts
at corrections... these are the wiggles that I attempted to
attribute to the TOF's when plotting angular acceptance of
each TOF and the calculated angular acceptance when using
the momentum of the particles arriving in each TOF. I think
they're TOF dependent wiggles and the fact that we see them in
lrn'ed MonteCarlo would mean it is something inside the
software.
I'm also crunching MonteCarlo with a 1mm offset in chamber 5 in
the +xWC-direction. The MonteCarlo was generated with the
proper geometry and is now being crunched with a geometry file
in which the middle right sector chamber is shifted. Hopefully
this will create a rise in right sector reconstructed beam
energy when electrons traverse, and a lower reconstructed beam
energy from protons - Just like the data shows.
All these results will be in by next wednesday
-e
Quoting Michael Kohl <kohlm@mit.edu>:
> Hi Eugene,
>
> 1) Can you make plots for BeamEnergy, Electrons and Protons where
> "with MASCARAD" and "no MASCARAD" are overlayed (with different
> colors
> or symbols)?
> 2) If possible, also real reconstructed data should be plotted
> overlayed,
> too.
>
> 3) Repeat 1) and 2) with energy loss turned off in comparison with real
>
> data.
>
> I'm still not convinced that internal radiation (MASCARAD) in
> combination
> with finite momentum resolution does not move average values.
>
>
> I discussed your latest plots with Vitaliy. We (or I) have some
> questions and remarks:
> a) What exact W-cut are you using for the profile histograms?
> b) Did you use the same W-cut for the real data in New_BeamEnergy.pdf?
> c) How does the W spectrum for real data compare with W.ps?
> d) Comparison between MASCARAD on and off is impossible if results are
> plotted in different panels with different scales.
> d) Electrons*.ps: Without MASCARAD, electron angle in the left sector
> seems shifted by 0.5s degrees but not in the right sector?! With
> MASCARAD, also electron angle in right sector gets a shift.
> e) Are the wiggles in the angular distributions also present in the
> data?
> f) BeamEnergy*.ps: Could the falloff of the reconstructed beam energy
> from
> proton coordinates at angles 60-65 degrees be due to the
> increasing
> energy loss (these are the slowest protons?
> g) Electrons_Masc.ps: when you subtract theta_e(p_e) from
> theta_e_crunch,
> what p_e are you using to calculate theta_e? Radiated or unradiated?
> If
> the radiated momentum is used, theta_e_calc will be off. You
> should
> rather construct theta_e_crunched - theta_e_tossed.
>
> Please save and send canvases also as *.root, this allows one to
> zoom in interactively.
>
> Thanks and best regards,
>
> Michael
>
>
>
>
> On Wed, 22 Feb 2006, Eugene J. Geis wrote:
>
> > I've included 7 plots here.
> >
> > Energy Loss is ON in both: MASCARAD on, and MASC off.
> > Strict W Cut is now included in ALL histograms except
> > W.ps
> >
> >
> >
> > W.ps - is invariant mass plotted on top of one another.
> > SLIGHT SHIFT... but very small. ~5 MeV.
> >
> > BeamEnergy_*.ps - Reconstructed Beam Energy from electron
> > and proton, a strict W Cut is included
> > for both MASC on and off. Beam Energy
> > drops ~5 MeV when MASC is on.
> >
> > Electrons_*.ps - Typical kinematic relations of ep-elastic
> > Looks bad for lowest Q^2 electrons.
> > Everything else is relatively flat. MC
> > would suggest to me to reject electrons
> > below 26 degrees.
> >
> > Protons_*.ps - Same Typical kinematic relations of ep-elas
> > for proton. Not good at all below 36
> > degrees and above 68 degrees. Also not good
> > below 320 MeV and above 900 MeV. MonteCarlo
> > would suggest to me that we should neglect
> > any events within those ranges, UNLESS elec
> > kinematics provide the proton information.
> >
> > New_BeamEnergy.pdf - For the heck of it, the actual data's
> > reconstruction of the beam energy. Same
> > color coding as the MC BeamEnergy postscript
> >
> >
> >
> > I believe I should now generate some Hydrogen Monte Carlo
> > with NO energy loss to be sure of the results. Dependency
> > on the discrepancies observed in proton theta will tell us
> > whether energy loss should be included in
> > reconstruction (both p and theta dependent), or should be
> > inserted after (p-dependent discrepancies only).
> >
> > I think:
> > If the former situation is the case, energy loss should be
> > put into Reconstruction and then kinematic corrections
> > should use the |MASCARAD on/E-Loss off| reconstructed Beam
> > Energy for the benchmark. If the latter is
> > true (p-dependent only), then kinematic corrections should
> > use the |MASCARAD on/E-Loss on| reconstructed Beam Energy
> > for the benchmark. Energy loss would be implicit in the
> > kinematic corrections and wouldn't even need implementation.
> >
> > Replies are expected and more than welcome.
> >
> > -eugene
> >
> >
> >
> >
> >
> >
> > ----------------------------------------------------------
> > Eugene Geis
> > PhD Student, Physics Department, ASU
> > Research Affiliate, MIT-Bates Laboratory of Nuclear Science
> > eugene.geis@asu.edu
> > ----------------------------------------------------------
> >
>
>
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>
>
>
>
>
>
>
--------------------------------------------------------------------------
Eugene Geis
PhD Student, Physics Department, ASU
Research Affiliate, MIT-Bates Laboratory of Nuclear Science
eugene.geis@asu.edu
--------------------------------------------------------------------------
http://quickreaction.blogspot.com
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