[Clascomment] OPT-IN: Shrunken particles pass freely through nuclear matter

[Lawrence Weinstein]

The results are excellent, but the paper can use some work in places.  I am not that familiar with Nature, but I assume that they want even more explanatory material than PRL since it is read by non-physicists.

The first two sentences after the abstract use far too much nuclear physics jargon and explain too little.  'High momentum transfer exclusive reactions' are not well defined.  It is not clear why elastic scattering is mentioned here.  The rest of the first paragraph is much better.

The second paragraph also could be clearer.  Do we expect non-physicists to know what Glauber scattering is?  I would also replace 'remain frozen' with 'remain small'.  Perhaps you can mention the expansion time of the hadron (~r/c) and how that is extended by time dilation to (~gamma r/c).   (I also prefer 'dilation' to 'dilatation'.)

p3: delete 'the' before 'color' on line 1.  
p3 para1: you refer to 'nuclear transparency' and to 'color transparency' without explaining the difference.

p3 para2: The production mechanism is not clear and the virtual photon in Fig 1 is not labelled.  Perhaps you should write that 'the incident electron exchanges a virtual photon with the nucleus.  The virtual photon can then fluctuate quantum mechanically into a q-qbar pair.  This virtual pair ...'

Also, I think that phrase 'materializes into a real meson' is too vague.  I assume that CT effects are determined entirely by the propagation of the 'real meson' in the nucleus.  Therefore, we should do a much better job of explaining 'materializes' and of the meson's propagation.  Should we discuss the propagation distance over which the SSC expands?

Delete the word 'intuitively' unless you explain it better.  As I understand it, rhos can be produced diffractively because they have the same quantum numbers as photons and pions cannot.
YOu might want to write that pion production, since it is nondiffractive, is more complicated.

p5 Methods: I suggest describing Delta decay so people know how those reactions produce two pions.
p5 last para: add '(sectors)' after 'spectrometers'

I apologize that my comments are so non-specific.  It is hard to write clearly and hard to edit clearly.



p3 para3: