[Clas_cascades] analysisnote_Lambda1520_v3

[Kijun Park]

Zhiwen Zhao wrote:
> Hi, folks
>
> I posted the Lambda1520 analysis note v3 on wiki and you can also get it 
> directly from
> http://www.jlab.org/Hall-B/secure/eg3/zwzhao
> /analysisnote_Lambda1520_v3.pdf
> This is for reviewing within eg3
> Please send me your comment and I really appreciate it.
>
> Zhiwen
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> Clas_cascades mailing list
> Clas_cascades at jlab.org
> https://mailman.jlab.org/mailman/listinfo/clas_cascades
>   
Hi,  Zhiwen.
Happy New Year~!
I would like to send you my comments for CLAS-note version 12/14/2010.
(I couldn't finish reading, so there is no detail comment on section5)

This is a great work and nice summary of your study. I am sure you did 
tons of work in detail, but you omitted many details in the analysis note.
You don't need to collect all my comments but I am pretty sure the 
committee will ask you some details.

GENERAL :
(1) Title : I suggest that "Measurement of cross sections and decay 
angle of $\Lambda^*(1520)$ off the deuterium."
(2) Abstract : "... angle distributions are extracted in the photon ..." 
=>"... angle distributions are extracted both channels in the photon ..."
(3) Fig 2: The models are not matching between left and right plots, 
especially red curve. (you said left one is zoom in from right plot)
(4) Fig 4: I don't get it the caption. (both are total cross sections)
(5) Lack of Lambda(1520) plots from data and simulations.

DETAILs:
(1) sec3: overall, I think you explained the corrections and cuts in 
general. You didn't show detail plots which you applied in this analysis.
Maybe, the review committee will ask you more detail.
(2) sec3.1: I wonder how you technically cut out beam trip in event basis.
(3) sec3.2: You may state how much % E-loss is and show a standard eloss 
plot.
(4) sec3.3: In my experience, you had better provide the momentum 
correction  plots  at least before and after.  This is analysis note for 
physics reviewer  NOT paper. Also, the correction is less than 10MeV 
level, which is ~ few%. Are you sure ?
(5) sec3.4: 7.7MeV tagger sag effect could be negligible (<1%) compare 
to others. Do you have any plot to show ?
(6) sec3.5: Could you explain why you choose pppi- channel for fiducial 
cut study ?
     Which proton is in the plot ?
     In this section, I think you had better provide at least fiducial 
function that you used.
     There IS pi- fiducial cut is shown in Fig.12(bottom): But you said 
no plot in text.
     Fig 12: quantify the kinematic range, instead of vertex position 
back, middle, front, momentum bin 1,2,3 etc.
     Better to explain the last yellow 1-D histogram, which is momentum 
dependence.
 (7) sec3.6: SC Occupancy Cut => TOF Occupancy Cut
     TOF counter number which you provided should be specified in terms 
of sector.
(8) sec3.7: the subtitle is "DC wire efficiency correction" but you 
explain only efficiencies ratio in terms of run period.
     And what GPP flags you used for three run periods ?
(9) Fig 13: 288 SC channels => 288 TOF counters
(10)Fig 14: Are they pK+K- count ? If so, is this better than 
$Lambda(1520)$ count ?
      Need to know how you choose the minimum(~120) and maximum(~380) 
C-counter range for fit.
      what is the "relative error" mean ? Does this come from by 
changing fitting range or function ?
(11) Fig18: The plots are after vertex Z cut ? If so, how some event can 
survive beyond cut ? If not, any target wall event ?
(12) sec3.11: Do we have any z-vertex correction in terms of momentum or 
sector ? If not, it would be better to see the consistent z-distribution 
in terms of sector.
       ".. which is 5cm larger ..." => ".. which is 10cm larger ..."
(13) Lambda(1520) is one of important plots in this analysis, but I see 
only this plot in Fig.38, 39.
(14) sec3.12: You may show the reference plots corresponds to cuts.
(15) sec3.14: Finite bin correction will be important issue to you. It 
would be better have a detail explanation.
(16) Fig.19: why pi- plot from MC is worse than others ? Due to log scale ?
(17) sec4.2: "..TDCs for the tgger .." =>"..TDCs for the tagger .."
(18) Fig22: This is plot from h+, h- not pi+, pi- because you said it 
assumed the pion mass. correct ?
       3sigma cut in red lines is based on delta t ? what is black lines ?
(19) I don't understand Fig24.  How you cam gain 40 times larger after 
BG clean-up ? From top to bottom plot.
      what is the BG subtraction you made ?
(20) sec4.3: page 35: last statement is true for proton channel too ?
(21) sec4.4.1: what is the red cut range ? Why you need K+ and K- with 
red curves in neutron channel in Fig 25.
(22) Fig 26: why tau vs. p plot from pK+K- is cleaner than one of pK0K- ?
(23) Fig 31 has less event than Fig 29, is this because of different bin 
size ? You mention you have a difficulty of statistics in neutron channel.
(24) Fig 32, 33: bottom 2x2 plots should be replace by  mean(sigma) vs. 
E_gamma for both data and MC in one plot. The current 1-D plots make me 
confuse at the beginning.
(25) Fig 34, 35: same and no captions.
(26) sec4.9:You may show the Lambda(1520) yield vs. E_gamma with and 
without phi(1020) cut.
(27) sec4.10: where "6900" come from ? Fig 38 shows the yield "7404"
(28) sec5.5: no show yield extraction plot ?
(29) sec5.6: no show acceptance plot ?
(30) Fig 53: you should separate the your data point with fit from world 
data because it is too complicate.
(31)Fig 62: difficult to distinguish between cross sections with and 
without phi(1020). Use different symbols and color.
(32) sec5.10: You'd better provide the more detail studies.

 
 




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Dr. Kijun Park
Jefferson Lab.
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