Minutes of the 2006/06/21 analysis meeting

From: Michael Kohl (kohlm@mit.edu)
Date: Wed Jun 21 2006 - 16:33:54 EDT


Hi,

below are the minutes of today's analysis meeting.
We meet again on Wednesday June 28, 2006 at 13:30 at Bates.

Minutes:

-ep/en Montecarlo now ready (Vitaliy)

-ep quasielastic (Adam):
  +Applying EG's corrections from elastic to deuterium quasielastic
  +p_e - Pcalc without corrections ~15MeV, with EG's momentum
   correction applied becomes ~5MeV, for pmiss<0.1GeV.
  +Should use EG's correction for theta_e as well to recalculate
   Pcalc, then see if p_e - Pcalc becomes zero.
  +Missing mass peaks close to neutron mass within 2 MeV for
   q.e. events including all missing momenta
  +Concluding: ready to extract physics.
  +Extract hPz from super ratio in quasifree limit
  +Extract hPz from comparison with MonteCarlo

-Aki:
  +Kinematic corrections from p(e,e'p) and p(e,e'p)gamma
  +Elastic channels overdetermined by three variables only, but need
   four corrections
  +Utilize radiative events to give fourth independent condition.
  +If method applied straight, yields unacceptably large angle offset
   of 2-3 degrees.
  +However, in p(e,e'p)gamma, offsets are evaluated at different
   momenta than in the elastic channel, hence need extrapolation of
   offsets to the elastic region. Results yields much smaller angle
   offsets.
  +All correction are currently parametrized as function of electron
   angle.

-ep elastic:
  +PRL draft being reviewed by MK, will send feedback to HG and CC

-ed elastic:
  +PK resumed analysis, work in progress, using Chi's ntuples
  +Pending on hPz
  +PRL draft being reviewed by MK, will send feedback to PK and JC
  +T20 analysis and drafting should be finalized first as T20 is utilized
   in T11 paper

-en quasielastic
  +EG to visit Bates from June 28 - July 22, 2006

-Misc.
  +Sasha Ilyichev to visit Bates in July 10-20
  +Mark Steadman to work on BLAST analysis from Jun 26 - Aug 18, 2006

Best 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 | |
+-------------------------------------+--------------------------+

---------- Forwarded message ----------
Date: Thu, 8 Jun 2006 11:35:49 -0400 (EDT)
From: Michael Kohl <kohlm@mit.edu>
To: "[BLAST_ANAWARE]" <Blast_anaware@rocko.lns.mit.edu>
Subject: Minutes of the 2006/06/07 analysis meeting

Hi,

below are the minutes of yesterday's analysis meeting.
Next week will be *NO* meeting. We meet again on Wednesday June 21, 2006 at
13:30 at Bates.

Agenda:
Assessment of status and near-term analysis goals

-ed elastic (tensor)
  +Update analysis for most recent recrunch (v18-2004, v19-2005)
  +Chi's thesis is based on earlier crunch version before geometry
   change, however changes for T20 results are small)
  +Spin angle determination was already updated and finalized by Chi
  +Chi gave tutorial for MK, TA, and RF
  +Review draft for publication

-ed elastic (vector)
  +Update analysis for most recent recrunch
  +Not clear how much time PK is able to spend on it
  +Incorporate spin profile
  +Need updated hPz from d(e,e'p) quasielastic analysis
  +Draft for publication being reviewed

-deuteron en quasielastic: GEn and e,e'n tensor, see powerpoint file
  +showed most recent extraction of GEn from 2004 dataset ver. v3_4_18
  +third and fourth Q2bin significantly higher than Galster
  +pmiss disagreement for highest pmiss bin, to considerable extent
   responsible for larger GEn values in third and fourth Q2bin
  +compare norm yield vs. pmiss with MC!
  +update kinematic correction for neutron (time-of-flight), derive
   neutron momentum correction from th_e, p_e, th_n
  +revision of timing calibrations, including left sector Ohio wall ...
  +Need updated hPz from d(e,e'p) quasielastic analysis
  +More Montecarlo studies needed:
  +e,e'n tensor asymmetries are finite even at pmiss->0, in agreement
   with the MC shown. Data is consistent with Vitaliy's
   analysis. However: MC used is in disagreement with Vitaliy's which
   gives zero asymmetries in the quasifree limit and which disagrees
   with the data
  +Vitaliy working on new MC but currently stuck in debugging, has only
   limited time available
  +Quasielastic MC essential for both e,e'p and e,e'n analyses, as well
   as ed vector elastic; recognized as bottleneck
  +Suggested that Eugene comes to MIT for three weeks in July, with the
   collaboration meeting embedded, work with Vitaliy on MC and shake
   down e,e'n analysis

-deuteron ep quasielastic
  +Apply Eugene's kinematic corrections, evaluate quality of corrections
  +Determine own kinematic corrections from comparison with MC
  +Waiting for MC from Vitaliy, apply spin profile
  +Determine hPz from asymmetry fit to MC with spin profile
  +Determine hPz from quasifree asymmetry analysis, use spin profile
   bin-by-bin
  +Thereby extract GEp/GMp from quasifree proton knockout
  +Extract spin profile from quasifree asymmeries using proton form
   factor parameterization, in order to investigate
   sensitivity/consistency
  +Re-evaluate AedV and AdT vs. pmiss, see if deviations "when the d-wave
   starts to dominate" with Arenhoevel are still present after latest
   recrunch
  +Determine Pzz from fit to AdT MonteCarlo

-deuteron inclusive e,e' and GMn
  +Nik's results are based on recrunch from before geometry update
  +Analysis needs to be updated, new kinematic corrections need to be
   applied
  +Re-run inclusive MonteCarlo with updated spin angle profile
  +Finalize extraction of GMn
  +Prepare paper (Nik provided a first draft before he left)

-proton inclusive e,e' N-Delta
  +Analysis based on v17, need to update to v20
  +Compare normalized inclusive yield before and after introduction of
   prescale factor for neutral trigger type 2
  +Montecarlo: Implementation of Polrad into DGen ongoing. Working on
   normalization of MC: Polrad starts only at pion threshold, and then
   calculates both inelastic + radiative yields
  +Below pion threshold and including elastic peak, Mascarad-MC should
   describe yield; at threshold, POLRAD and MASCARAD should be smoothly
   connected
  +Verify implemented codes: Estimate yield du to radiation tail from
   elastic scattering in delta region by hand, evaluate manually how
   this affects asymmetry in delta region, compare to Polrad result
  +Sasha (Alexander Ilyichev) has been invited to visit Bates in July,
   week before and including collaboration meeting. Task is to make
   implementation reliable
  +Desirable to also implement radiative MC for exlusive pion
   production channels. Aki, Yuan, Tavi: what can be done in
   preparation before Sasha comes?

-p(e,e'pi+) (Yuan), see powerpoint file
  +Large fraction of good e,e'pi+ events is triggered by piplus(!)
  +In previous analysis it was required that electron is self-timed,
   likewise that the assigned flighttime is shorter than that of the
   pion. However, this is generally not the case for e,e'pi+ events and
   a large fraction of events got discarded
  +Apply Cerenkov info to identify electron only in those events where
   timing information was insufficient to clearly identify the electron
   (which was the case in only 2% of the good events).
  +This means that most good events for which Cerenkov would have been
   inefficient are recovered by timing-based pid
  +Total number of e,e'pi+ events now in agreement with Aki's analysis,
   ca. 45k
  +No kinematic corrections applied: Missing mass only 8 MeV off
  +Double asymmetries: versus W, all Q2 in one bin:
  +Yuan's and Aki's asymmetries in agreement within 1 sigma or
   10-20%. However: these data are 100% correlated (identical). So:
   what's the reason: compare runlist, recrunch version, charge in each
   spin state, yield in each bin, ...
  +Slight disagreement between data and MC
  +Q2 vs W acceptance shows a hole in MC at Q2~0.16-0.18, likewise
   theta_e ~39-42 degrees
  +Q2 dependence: choose 3-4 Q2 bins, 7-8 instead of 15 W-bins
  +Waiting for final hPz from ep elastic
  +Spin angle profile in MC?
  +Implementation of DMT and Sato-Lee: Chi provided skeleton in DGen
  +Extract polarized response functions RT',TL' etc.
  +Vary SMR=Re(S1+/M1+), EMR=Re(E1+/M1+) in MC, study sensitivity of
   T', TL' and extract deformation parameter
  +Analysis of pi0 channel

Best 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 | |
+-------------------------------------+--------------------------+



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