Hi,
there is no analysis meeting tomorrow; however, we will meet at 13:30 to
have a rehearsel of Bill Franklin's talk at SPIN2006 and also of my talk
at the Bates symposium later this week.
Best regards
Michael
On Thu, 21 Sep 2006, Michael Kohl wrote:
> Hi,
>
> below are the minutes of yesterday's analysis meeting.
>
> Only in case of a particular need we will hold a meeting next Wednesday
> 2006/9/27. In any case there will be a rehearsel for Bill Franklin's
> presentation for SPIN2006, either at 13:30 or directly after the eventual
> meeting.
>
> We still have not decided on moving the meeting schedule.
> Latest suggestion is every other Thursday at 9am. Let me know if you can
> accomodate this with your schedules.
>
> Best regards,
>
> Michael
>
>
>
> Minutes
>
> -Status v3_4_21 recrunch (MK)
> +See ppt
> +Recrunch of runs 7002-16506 complete using run-by-run time
> calibration generated by Mark
> +Presently evaluating quality, see ppt
> +Looking at three time correlations, for (e,e'p), (e,e'gamma) and
> (e,e'n) events: if calib is correct, all measured time diffs should
> agree with the time diff calculated from tracking, for all detector
> pairings (16x16 TOFsxTOFs and 16x72 TOFxNeutron bars)
> +Results are complete for hydrogen runs 12144-13278 and look very good,
> (mean,sigma) for deltaT(e'p) without any further cuts except vertex
> and track charge gives (-2.4ns/1.8ns) in v20, becoming (0.2ns/0.9ns) in
> v21!!!
> +Will announce victory (and update th links in RECRUNCHDIR) after having
> completed the quality checks on the entire dataset
>
> -Comparison data/Montecarlo for d(e,e'p) (AD)
> +See files in folder DEGRUSH
> +Montecarlo vs data for several variables for 2005 deuterium
> +Normalized MC to maximum bin in each panel
> -> Better uses only one global normalization, this gives a better
> feeling for local inefficiencies
> +Data with Cerenkov cut, inefficient (nonexistent) for rear angles,
> ->relax this cut for this investigation
> +Considered MC uses Geant only for acceptance test but tossed
> variables otherwise. Therefore, resolution (convolution with
> estimated resolution function) has to be adjusted manually
> +vs electron momentum: quite some disagreement in higher Q2 bins,
> could be due to cerenkov cut
> +vs. phi: disagreement at forward angles already present in AM's
> thesis
> +This MC choice was made to facilitate the variation of input
> parameters (GEn,GMn,GEp,GMp) that affect event weights. This way
> only one common event list needs to be generated
> ->event-weighted versus reconstructed MC
> +As the event-weighted MC has no energy loss, data yield should be
> energy-loss corrected (in average) before comparing with MC, all the
> multiple scattering and Landau broadening then needs to be modeled
> manually to give a realistic response (Gaussian smearing).
> +EG has used Geant-MC to determine a parameterization of the energy
> loss effect as a function of particle's energy, will send the result
> in a separate email
> +At least one detailed MC including reconstruction of propagated
> events for one parameter choice of G_E,M^p,n with all multiple
> scattering and eloss effects turned on in propagation and average
> Eloss corrections applied in reconstruction is necessary to evaluate
> the quality of the event-weighted MC (->EG)
> +need to look at variables such as theta_e, theta_p, TOFnum, CERnum,
> missing momentum components longitudinal, sideways within the
> scattering plane and out-of scattering plane (in the physics
> coordinate frame) for data/MC comparison
> +When Eloss is applied to data and resolution modeled in MC, the
> remaining shifts between MC and and data can be used to parameterize
> kinematic corrections for the d(e,e'p) channel
>
> -(e,e'n) analysis (EG)
> +Showing asymmetries and MC for v3_4_21 2005-deuterium (see ppt)
> +v21 data doesn't look drastically different from v17 except at
> certain locations. However, both do not look "satisfactory".
> +There are regions of disagreement between MC and data regardless of
> what is assumed for GEn, resulting in a chi^2/d.o.f. at the minimum
> much larger than 1, also the chi2 distributions do not look
> parabolic in those cases (1st and 2nd bin)
> +There is a technical problem in regard of activation of the proton
> veto from the wire chamber hit multiplicity. Since the
> lrd-recrunches (v17-21) are done from the DST which only contains track
> information, multiplicity variables are unavailable unless the
> ntuples were generated with lrn from raw data. Therefore,
> lrn-generated ntuples (v14,=ANALDIR) need to be accessed to process the
> multiplicities in parallel with the events from the lrd-generated ntuples.
>
> +Earlier on the phone we discussed a number of steps and detailed
> checks that need to be done regarding:
> +Data/MC yield comparisons in various variables, such as z,
> theta(e,n), phi(e,n), mom(e,n), pmiss (also components);
> +(e,e'n) rate monitor (after good cuts) vs run number and
> vs. detector channels;
> +Not mix things when doing comparisons between version
> (e.g. different runlists)
> +On time correction for neutron: Tnn is based on tdcdiff
> measurement and pathlengths for electron and neutron. The
> corrected electron track along with the neutron angles allow to
> calculate Tnncalc. Comparison of Tnncalc with Tnn should be
> used for event selection instead of missingmass (this way
> negative Tnn's or shorter than photon-Tnn in case of a
> miscalibration would not be rejected through the Mmiss evaluation)
> +In the previous version of correcting Tnn, the difference
> Tnn-Tnncalc was first parameterized as a function of Q2 and then
> this function was used to correct Tnn event-by-event (i.e. the
> correction itself was averaged)
> +Plan: use Tnncalc for further processing of quantities that
> depend on neutron momentum (this way the correction is
> event-by-event and not averaged). Hope is that the uncertainty
> of Tnncalc is less than for Tnn from the time measurement.
> +A way to verify that Tnncalc has a better resolution than Tnn
> would be to compare reconstructed vs. tossed MC values of these
> two variables (if there wasn't the pathlength problem in MC).
> +Also, the MC for the first and second bin look suspicious,
> contracting to zero at pmiss ~=0.16-0.20, but not in the third and
> fourth bin. VZ tried to convince me that this is real (or at least
> in Arenhoevels calculations), but a zero-sensitivity to a variation
> of GEn is hard to understand. Anyway it is important to also compare
> the MC yields with data yields for the same bins/plots!
>
> -aob
> +status prl: confirmed receipt; 4 lines too long
> +collaboration meeting on Friday 2006/11/17
> +new meeting schedule: proposed every other Thursday 13:30
> with occasional Bates Lunch seminars with 3pm limit to commute to
> campus for departmental colloquium. HOWEVER: Adam may have classes
> from noon on, and there may be senior campus lunch meetings.
> Therefore we consider every other Thursday at 9am.
> LET ME KNOW IF YOU HAVE OBJECTIONS!
>
>
> Regards,
>
> Michael
>
>
> +-------------------------------------+--------------------------+
> | Office: | Home: |
> |-------------------------------------|--------------------------|
> | Dr. Michael Kohl | Michael Kohl |
> | Laboratory for Nuclear Science | 5 Ibbetson Street |
> | MIT-Bates Linear Accelerator Center | Somerville, MA 02143 |
> | Middleton, MA 01949 | U.S.A. |
> | U.S.A. | |
> | - - - - - - - - - - - - | - - - - - - - - -|
> | Email: kohlm@mit.edu | K.Michael.Kohl@gmx.de |
> | Work: +1-617-253-9207 | Home: +1-617-629-3147 |
> | Fax: +1-617-253-9599 | Mobile: +1-978-580-4190 |
> | http://blast.lns.mit.edu | |
> +-------------------------------------+--------------------------+
>
+-------------------------------------+--------------------------+
| Office: | Home: |
|-------------------------------------|--------------------------|
| Dr. Michael Kohl | Michael Kohl |
| Laboratory for Nuclear Science | 5 Ibbetson Street |
| MIT-Bates Linear Accelerator Center | Somerville, MA 02143 |
| Middleton, MA 01949 | U.S.A. |
| U.S.A. | |
| - - - - - - - - - - - - | - - - - - - - - -|
| Email: kohlm@mit.edu | K.Michael.Kohl@gmx.de |
| Work: +1-617-253-9207 | Home: +1-617-629-3147 |
| Fax: +1-617-253-9599 | Mobile: +1-978-580-4190 |
| http://blast.lns.mit.edu | |
+-------------------------------------+--------------------------+
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