[Clas_cascades] Comments on analysis note

[Hovanes Egiyan]

Hi Elton,

thanks for the reading the note and sending me the comments.  I 
implemented them
and submitted the note to CVS.

Hovanes.


Elton Smith wrote:
> Hi Hovanes,
>
> Hre are some suggestions to the analysis note;
>
> title page, abstract
>
> - Add "We set set limits on the production of a Xi-pi- narrow state,
> searching in 20 MeV mass bins over mass range of 1.49 < M(Xi-pi-) < 2.2
> GeV, of less than 3 nb. In the mass range corresponding to the observation
> near the mass M=1.86 GeV, we set a 90% CL upper limit of less than 700 pb.
> The experimental resolution of the Xi-pi- mass is sigma=7 MeV.
>
> Question: 1. How do our limits depend on the mass window?
>   
Changed the abstract.
> p. 35. last sentence and first sentences on p. 37:
>
> I would give specific numbers from the analysis note: The measured cross
> sections in eg3 for 4.5 < Eg < 5.0 GeV are higher than fitted g11 cross
> sections by 9-14% depending on parameters of the fit, which were
> determined over the interval 2-5 GeV. We take the normalization
> uncertainty of the eg3 data to be 15% with a systematic uncertainty of 5%.
>   
I added this to the text in the analysis note. There is 5% relative for 
the cross sections is coming
from the decays outside ST.  I  am not sure it is useful to quote an 
uncertainty on an uncertainty.
> p. 36 Fig. 22. 'Black' and 'Red' lines interchanged in caption. Add
> (nominal configuration for data) following 'Black' lines.
>   
Fixed the caption.
> p. 37, Section 11 Systematics
>
> We should add a table of systematic uncertainties with the major
> contributions. As I understand it, these are
>
> Source                                            Systematic Uncertainty
> Cross section model dependence                    20%
> Start Counter Acceptance for decaying particles    5%
> Trigger efficiency                                10%
> Quadrature sum                                    23%
>
> State in the caption that use 30% overall systematic uncertainty.
>   
Added a table listing the uncertainties.  The trigger efficiency 
correction is 15%, I forgot to
change it there. But I not understand 30% and put 26% instead.

> p. 39 top. In the section about estimating upper limits, I would state
> that we use a systematic uncertainty of 30%.
>   
Added a centence stating that we use 26% systematic uncertainty in the 
upper limit estimations.
> p. 49, Fig. 29. Add statement that this comparison ignores systematic
> uncertainties in the computation of upper limits, and is presented for the
> purpose of comparing various schemes for obtaining upper limits
>   
Done.
> p. 50. Add note that this comparison is made for fixed acceptance
> uncertainties of 30%, and the Rolke method will be used as our nominal
> method for extracting upper limits.
>   
Done.
> p. 51 Section conclusions (see previous questions)
>
> Add he experimental resolution of the Xi-pi- mass is sigma=7 MeV. (I took
> this from p. 27).
>   
Done.  Added a section from my study described at
http://clasweb.jlab.org/rungroups/eg3/wiki/index.php/Optimal_summing_range_selection_for_upper_limit_estimation.
> Also, do we have an estimate of the dependence of the upper limits on the
> mass window used to extract it? We should add this to the conclusions and
> will need it for the paper as well.
>   
We do not have an estimate of this dependence. Need to discuss this.
> Thanks, Elton.
>
> Elton Smith
> Jefferson Lab MS 12H5
> 12000 Jefferson Ave
> Suite # 16
> Newport News, VA 23606
> elton at jlab.org
> (757) 269-7625
> (757) 269-6331 fax
>