[Clascomment] OPT-IN:Absorption of the omega and phi Mesons in Nuclei

[Stepan Stepanyan]

Mike et al., 

Here are few of my comments on your paper \"Absorption of the \\omega and \\phi Mesons in Nuclei\".

General comments:
(a) CLAS already published two papers on (\\phi N) cross section, both from photoproduction data on deuterium.
In both cases large cross section for (\\phi N) interaction is observed. Clearly deuteron is not a dens nucleus
and in-medium modifications are quite small. One of the main conclusions of that studies is that \\omega-\\phi
mixing can generate large (compare to VMD prediction) cross section for (\\phi N). See PLB 680, 417(2009) or http://arxiv.org/pdf/0907.2668v3. Did you took into account \\omega-\\phi mixing, J.M. Laget has done
original calculations for the above reference.
By the way this article should be cited in your paper as well.

(b) Your result on large \\omega absorption is based on the number of \\omega\'s extracted from Fig. 1. Just
by looking on Pb histogram, it does not look like systematic error on this number is ~20%, it more like
100%. Can you explain distribution for Pb in Fig. 1. For example, your selection range is 0.75 to 0.82 GeV,
your bin size is 0.02 GeV, so you use 3.5 bins. From that plot the first two bins have 3-4 counts, while next 
1.5 bins have (negative) -12 to -15 counts. So what is the number of \\omegas here? 

(c) For \\omega you used mass range 0.75 to 0.82 GeV (70 MeV). Your results indicate that in-medium 
width should be > 200 MeV. Some of your \\omega\'s will decay before getting out from nuclear medium and
hanse will have larger width than what is in vacuum. Am I correct to say that you would expect \\omega\'s 
outside of your selection, in particular in the range 0.85 to 0.95 GeV where you normalize \\rho distribution
and therefore you artificially increase normalization of \\rho. Also, small (compare to width) integration range 
will cause problems itself, you may be missing large fraction of \\omega\'s, is not it.   

(d) what is the relation between Fig. 1 of this article and Fig. 10 of [9] (your previous publication). Why they 
have so different statistics? 

Additional comments:
(1) Ref. [20] is for \\rho and \\omega, and has nothing to do with \\phi. Please remove it from line 79.
(2) Above CLAS paper and the results of both CLAS deuterium analysis for \\phi N cross sections must be quoted in
the discussions, e.g. on page 3 right column.
(3) is the combinatorial background subtracted in Fig. 1
(4) negative counts in the invariant mass distributions after subtraction of \\rho is not well explained. Saying  
\"may be indicative of \\rho-\\omega interference\" is not a good phrase. Besides if I look your Fig. 10 from Ref.[9]
it does not look like should be any negative counts for Fe-Ti. Can you explain this? Could this just be a simply 
bad normalization? 
(5) why there is a empty line (176) between two paragraphs on right column of page 2. Seems an empty line 
(space) will be more appropriate between lines 192 and 193.