Dear Peter,

as promised in my previous mail, I read the paper and have some  comments.
The paper is well written and it is a real pleasure to read it. As  Werner 
I'm really impressed about the amount of information which you  squezzed 
out of these few events.

a) As already mentioned, the paper should be made public to the  collaboration 
with the author list

--> included

b) 3.1, 1. para, last sentence: the way you treat the vertex position  seems 
to me unmotivated. The reader doesn't know whether the fitted  vertex or the 
wire position is more precise. This needs one more  sentence to justify your 
procedure.

--> done

c) 3.1 right column. You use S/sqrt(S+B) and explain the meaning of S  and B 
only in the next paragraph. Can this be changed?

--> done

d) 3.2, 2. para, last sentence: ... to which selection criteria had  been 
applied.  Which criteria? Most likely the same as for data, but  this has to 
be mentioned.

--> done

e) Fig. 2a: The referee will ask you why the MC curve left to the  signal is 
shifted. The region from 1.6 - 1.7 would look better if the  MC curve is 
shifted by one bin to the left.

--> We investigated the peak; it is most likely a fluctuation. Please
--> have a look at our answer to a similar remark by Alan. At
--> http://www-f9.ijs.si/~krizan/herab/open_charm/paper/referees/d0-residuals.eps 
--> you can find a plot which shows the residuals (difference in the 
--> measured and fitted number of entries in units of sigma) for Fig 2a. From 
--> the plot we deduce that the observed 'peak' at 1.58 is most probably a 
--> fluctuation. This is supported by the distribution for individual targets 
-->(Fig 8 in the note, http://www-hera-b.desy.de/subgroup/physics/herab/analysis/mb2003/open_charm_articles/note_061017.pdf).  
--> On the other hand, a slight discrepancy between the ansatz and the real 
--> background form cannot be excluded. The corresponding impact on the signal 
--> yield is small, and has been included in the systematic error (under 'event 
--> fitting'), and its evaluation is described in the note. Note also that the 
--> ccbar background disapears above 1.75GeV (see Fig 7 of the note). Chi2 of
--> the fit is 92.4/84 dof, prob = 25%.


f) page 6, left column, 6 lines below eq. 2: was assumed to be  ????  Please 
finish this sentence.

--> A % sign too much ... Corrected.

g) Table 5: where is the lumi error of 3.4% coming from? Calculated  from the 
lumi paper taking into account the correlated error?

--> Yes. In fact, there is a typo in the table. It should be 3.7 instead of 3.4,
--> corrected.

h) page 7, left column, 2. para: when you describe Fig. 5, you should  mention 
that the old results where updated for branching ratios.

--> done, footnote

i) page 10, left column, 2. line: why is the lumi error per wire  2.5%?? They 
are much larger.

--> This is the error in alpha, not in lumi. Note that all correlated error drop out.
--> The error on alfa was calculated by using a toy MC: we smeared the 
--> cross sections per wire by the  uncertainty in luminosity and due to 
--> finite MC stat. The contribution from luminosity is ~2.2%, from MC ~0.6%, 
--> in total 2.3%. In the paper we still had the old number 2.5%, corrected.


j) page 10, sec. 6, 8. line: were measured: ...

--> done

k) Ref. 1: Energy not energy

--> done

l) Ref. 14: et al without 2007. (2007), not (2006)

--> done

m) Ref. 19: page 312

--> done

n) Ref. 23. remove R after Battiston

--> done

o) I. Abt et al. This is not hep-ex

--> done


With best regards,