[Clascomment] Sigma Ad Hoc -Extended review

[Reinhard Schumacher]

Dear Sergio, Mike, et al.,

	I have looked at the new version of the K+ Sigma- paper, and I am 
impressed by the improvements.  The paper looks better (i.e. more 
convincing) than before.  Let me make some specific remarks about what I 
see.

Figure 1: Having the dotted line that represents the background 
contribution makes the whole graph make better sense to me.  The figure 
caption and the claimed "3 sigma" cut now look fine.

Figure 2: This is much better with the overlay of the Monte Carlo 
spectrum.  The reader will now be satisfied that the CLAS resolution for 
this situation just happens to indeed look sort of like a Lorentzian 
function.   I don't think it detracts from the message that the curves 
are a little hard to tell apart.   That is what we want!

Figure 3: Very impressive.  It is now clear at a glance that at the 
higher energies the cross section goes up in the backward direction. 
Not only that, but the theory absolutely fails in the backward 
direction, but an order of magnitude.  This latter observation was not 
visible in the previous version of the plot.  Thus, plotting on the 
semi-log scale shows both the data and the theory better, and that can 
only help the impact of the paper.

This can be highlighted in the text.  At the end of page 4 you already 
mention that u-channel may be present, so I would leave that sentence 
alone.  But on page 5 near the end of the left column you have a 
sentence "The model, however, overestimates..."  What you have stated is 
not a accurate as it could be.  How about:  "The Regge-based model 
overestimates our results at forward and intermediate angles by about a 
factor of two.  At backward angles the calculated cross section is too 
small by an order or magnitude, which is a reflection of the lack of 
resonances in the model."

I think with these changes I have no other objections to sending off the 
paper for publication.

Regards,
Reinhard.

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Reinhard Schumacher                            phone: 412-268-5177
Department of Physics, 5000 Forbes Ave.        fax:   412-681-0648
Carnegie Mellon University                     email: schumacher at cmu.edu
Pittsburgh, PA 15213, U.S.A.         web: www-meg.phys.cmu.edu/~schumach
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