Dear K2K collaborators,
We had a K2K conveners meeting on May. 12th.
The minutes are available now.
In addition, you can find all presentations on the web with a regular K2K
password.
Enjoy!
T. Nakaya
+++ Minutes of K2K conveners meeting on May. 12th, +++
>
>*************************************************************
>Date & Time : 5/12 (Thu) 8:00-12:00 (JST)
>
Presentation files at http://neutrino.kek.jp/internal/conveners/meeting/050512/
>*************************************************************
>
>8:00-8:40 (25 min. talk + 15 min. questions/discussion)
> [1] HARP K2K target result -JJ
http://neutrino.kek.jp/internal/conveners/meeting/050512/status-harp.pdf
The status of the Harp/K2K analysis was presented. A selection of results
showed that
Harp has excellent tracking efficiency and PID. The redundancy of the
detector allows the selection
of pure and unbiased data samples which agree well with MC samples.
A preliminary result on the cross section, including fits to SW
predetermination were presented.
The result agrees well with previously published data, but Harp error is
much smaller.
Final results on the cross section, at the 5% level or better will be
presented on 24th of May.
The translation to Far/Near ratio is proceeding in parallel. Machinery is
ready to produce
a far/near ratio with covariance matrix as soon as the harp result is input.
The aim is to make available the result on June 7th and to present a final
result (including far/near ratio)
at the collaboration meeting.
>
>8:40-9:00
> [2] K2K oscillation analysis overview and strategy -T. Nakaya
http://neutrino.kek.jp/internal/conveners/meeting/050512/osci_ana_intro_nakaya.pdf
A strategy of the K2K oscillation analysis toward the collaboration meeting
was presented.
We will make the final data set for the oscillation analysis this time.
In nm_mu disappearance analysis, we use almost the same analysis method as
the previous one.
Each detector group should fix the spectrum fit result by May 20th, and we
perform the merged fit by the end of this month.
The first result of the SK oscillation analysis is expected by the week of
June 6th.
In nu_e appearance search, we update the data set with 9.2E19 POT (4.8E19
POT before).
We apply a "pi^0 cut" to suppress the background events.
We expect the new result at the June meeting.
>
>9:00-10:00
> [3] SK update
> [3-1] Final K2K-SK data set -K. Kaneyuki
> [3-2] nu_mu disappearance -K. Kaneyuki
> [3-3] nu_e appearance -K. Kaneyuki
http://neutrino.kek.jp/internal/conveners/meeting/050512/SK_050512.ppt
The final check of K2K-2 reprocessed data were presented, which showed the
better OD
agreement with MC, and which had improved QE correction, ring counting and
particle identification.
With the new K2K-2 data set, the number of FC1Rmu is 28 (30), the number of
1Re is 6 (7),
and the number of muti-ring events is 23 (20) in the new (pervious) data set.
[HW1] We should check why two events in K2K-II 1Rmu sample are changed even
though
MC expects no change.
Although MC does not predict the change of the number of events in 1Rmu sample,
the actual events (contents) are changed. So we should study the
change systematically.
In nu_mu disappearance analysis, we have 58 1Rmu events in total.
The best fit oscillation parameter is (sin^22q, Dm^2)=(1.0, 2.76E-3 eV^2)
in the physical region, and
the null oscillation probability is 4.0 sigma. The SK oscillation analysis
is almost ready when the
updated flux, F/N and nQE/QE ratio come from the near detectors.
In nu_e appearance analysis, the performance of POLFIT was studied with an
atmospheric neutrino
data sample. A general performance looks good, but more systematic check is
necessary.
There are many comments about the nu_e analysis as shown below.
[HW2] We should show the two-gamma invariant mass distribution found by POLFIT
in the SK-II atmospheric neutrino data.
In the meeting, only SK-I data are shown.
[HW3] Compare the energy and the opening angle of the second ring found by POLFIT
with atmospheric neutrino data sample .
[HW4] Please carefully compare the SK-I result with the SK-II one.
[HW5] The uncertainty of water parameter for the second ring found by
POLFIT must be studied.
[HW6] It may be difficult to use two ring mu-e sample for a systematic check.
>
>10:00-11:30
> [4] Near detector analysis update, and the plan for June K2K meeting
> [4-1] 1KT (20+5 min.) - M. Shiozawa
http://neutrino.kek.jp/internal/conveners/meeting/050512/KT-shiozawa-20050512.ppt
Goals by the June meeting are;
(1) Nsk, (2) spectrum, (3) nue flux, (4) pi0, (5) mupi0, (6) nuclear gamma,
and (7) proton tagging. Among them, we'd like to publish KT papers in future
on; (1) NC measurements, (2) PDK BG, and (3) KT detector.
Reprocessing of whole K2K KT data and mass productions of MC are almost done.
Preliminary Nsk value is ready while we need to recover some missing runs
and 99 data. Systematic uncertainties will be updated soon. 1st trial
of spectrum fitting was performed. Program runs well but several items
to be checked/done; reason for larger chi2, distribution change, update of
errors and so on.
> [4-2] SciFi (20+5 min.) - M. Sakuda
http://neutrino.kek.jp/internal/conveners/meeting/050512/SciFi050512.pdf
They are producing plots and spectrum with new MC considering new measurement
of the accurate fiducial mass (+-1%). This lowers the energy loss in SciFi
detector by 15 MeV and give better chi^2 to the spectrum fit.
They will do the spectrum fit with K2K-1 and -2a data sets by May 20.
They will present other analyses (K2K-2b,2c) at K2K Collab.Meeting.
Status of MA paper: 2nd draft will be circulated among the paper committee
after the numbers are updated for new MC.
> [4-3] SciBar (20+5 min.) - M. Yokoyama
http://neutrino.kek.jp/internal/conveners/meeting/050512/SciBar_masashi.pdf
CC coherent pion paper has been circulated to the collaboration.
The deadline for comments is May 13.
The paper will be submitted in ~a week after one more circulation for final
confirmation.
All data were reprocessed with updated tool and K2K-IIc data (~15% of
K2K-IIb) are added.
Spectrum fit code is ready and basic distributions are checked.
Treatment of low-q^2 part needs check and discussion with other detectors.
There are 10 other analyses ongoing within the group (6 for CC interaction,
2 for pi0 and beam nu_e, 2 for NC).
List of analyses and a few example were introduced.
> [4-4] MRD (10+5 min.) - T. Ishii
http://neutrino.kek.jp/internal/conveners/meeting/050512/MRDconv050512.pdf
Off-spill data for the whole K2K experiment have been analyzed (Marat).
The off-spill data show the stability of the MRD detector.
Based on the detector stability, the summary table of the event rate
has been updated. The Nsk table has been also updated (Juneho).
The Nsk should be renormalized according to the SK efficiency change.
> (*) +5 minutes for questions and discussions
>
>11:30-12:00
> [5] Discussion for the June K2K meeting
>
>12:00-12:15
> [6] Expression of Interest to a new neutrino experiment at FNAL.
> The SciBar detector at FNAL Booster Neutrino beam line - T. Nakaya
> Note: This is not the part of the K2K experiment, but it uses the
K2K SciBar detector.
> So, we would like to introduce this experiment to the K2K
conveners at first.
http://neutrino.kek.jp/internal/conveners/meeting/050512/SciBar_at_FNAL_nakaya.pdf
There is an expression of interest to a new neutrino experiment at FNAL
with the K2K-SciBar detector.
A main physics motivation of the experiment is to measure the neutrino and
anti-neutrino
cross sections around the energy of the T2K neutrino beam (~0.7GeV).
If FNAL makes the experimental hall within a year, we will ship the
K2K-SciBar detector
to FNAL to start the experiment in 2006.
We expect that the budget situation is more clear around summer~fall 2005
when the FNAL 2006 year budget is valid.
>
>============================================================
>To each convener, please remind the subjects of this conveners meeting
>============================================================
>* The final result of Spectrum and N_SK from each near detector group for
the oscillation analysis
> o Spectrum and N_SK with systematic errors.
> o Supporting plots to show analysis quality.
>* Status report of SK oscillation analysis.
>* Status report of physics analysis in each group.
>* paper status
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