Pre-Approval Comments, 24th March 2014 :

Name Comments
George This physics results of this analysis are connected to the
results from 14-003 K0,Lambda. Are the analyses coordinated , e.g. - pt
bins, multiplicity bins, methods, etc ?
Monika The codes are different and the pt bins are optimized for
this analysis (so, not the same), but multiplicity bins , event
selection , track selection are same.
George The codes are different and the pt bins are optimized for
this analysis (so, not the same), but multiplicity bins , event
selection , track selection are same.
Monika For now the differences between the values in the points are
take from the largest multiplicity bin and the % difference is assigned
as syst for all bins. However, we see that this is still affected by the
statistical uncertainty in each data point, so the plane is to combine
all multiplicity bins to have the larges statistics and then vary cuts
to see how the result changes and assign the syst uncertainty.
What are stat error : s 27, 28, - what are the stat errors ? shown on s
21 -- significance is small , efficiency is small
  ***All agreed that the uncertainty fluctuations bin-by-bin on s 29 are
not physical and the above procedure should be applied.
Steve what is the average eta for the measurement and how does this
compare to other analyses?
Monika The range is different from Ks and Lambda, because the ECAL
acceptance in different.
Julia It is worthwhile to compare the results for all particles
with the same eta bins, since v2 may depend on eta and we don't know
how, but the pi0 analysis can not extend the eta range. We would need
the K0 and Lambda analysis to make the same cuts as pi0; then we can
compare the same eta.
Matt Related to this question: the efficiency is not constant for
pi0 as a function of eta, so we need to see if and how the result
changes after the efficiency corrections are applied
Monika This is on our todo list
Gunther In the highest multiplicity classes v2 of pi0 is above that for
charged hadrons at low pt. Is that what we expect base on the yields
measured in 12-016 ?
Monika similar trend is seen in the RHIC results in s 4
Julia It is worthwhile checking the consistency of the charged
hadron and pi0 , Kshort results for v2 with the assumption that charged
hadrons comprise just pi,k,p .
*** consistency check using 13-002 , 12-016, this analysis and Ks,
Lambda ( will have to assume the v2 of protons = v2 of lambda)
the phi analysis -- useful to look at closure test on MC . It
would be helpful to check if all errors and uncertainties propagate the
way you think
Monika * will add a HIDJET study in the AnNote -- still to do
Christof s 11: do you understand the background shape, in particular the
undershoot at low mass
Monika Yes, we have don a great deal of study for the PbPb paper
11-009. The undershoot is due to photon conversions. This a correlation
that is not present in the mixed event BG. This undershoot does not
affect the result.
Federico Why don't you just perform a fit using a
parabolic shape of the BG ?
Monika Why don't you just perform a fit using a
parabolic shape of the BG ?
Frederico Why don't you just perform a fit using a
parabolic shape of the BG ?
Monika same event selections as published analysis . Will check
with the experts
Frederico ECAL spikes -- in the end you decided not the cut them . So
what's the contamination from the spikes in your sample ? Isn't this
affecting your v2 estimate?
George Monika: same event selections as published analysis . Will check
with the experts
Monika does not have an answer now. will check
George about varying the sidebands and including this in syst,
Monika yes this was done a documented.

Matt, Christof and all agree that the analysis is in good shape and the
ARC is already onboard. Analysis preapproved. Remaining questions will
be followed up for approval.

-- RaviJanjam - 16 Apr 2014 -- MonikaSharma - 22 Apr 2014

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