<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div>Hi Silvia, </div><div><br></div><div>just a few short comments in reply. Greetings - Sebastian</div><div><br></div><br><div><div>On Dec 19, 2014, at 5:39 AM, Silvia Pisano <<a href="mailto:silvia.pisano@lnf.infn.it">silvia.pisano@lnf.infn.it</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div dir="ltr"><div><br></div><div>Dear Sebastian,</div><div><br></div><div>...</div><div><br></div><div>----------------</div><div><br></div><div>Your point about the c12 has been raised during our Ad Hoc review. We checked already at that time the form of the distributions, fitting it with the addition of a constant term. The results are in </div><div><br></div><div><a href="http://www.lnf.infn.it/~pisanos/dvcs/prd/c12/?play=http://www.lnf.infn.it/~pisanos/dvcs/prd/c12/test_bsa_c12_nh3_noden.png">http://www.lnf.infn.it/~pisanos/dvcs/prd/c12/?play=http://www.lnf.infn.it/~pisanos/dvcs/prd/c12/test_bsa_c12_nh3_noden.png</a><br></div><div><br></div><div>First plot shows the comparison among the two asymmetries, and, even though the c12 - red points - are usually bigger than the nh3 ones - blue points, they are compatible for almost all of the bins. The middle and right plots show the fit to the c12 (middle), nh3 (right) bsa with the standard bsa function, where p0 is the constant term and p1 the sinphi modulation. As you can see, p0 for c12 is compatible with 0 in 1.5 sigma. The other modulations are perfectly compatible.</div><div><br></div><div>Bear in mind also the fact that these are raw asymmetries, not pi0 subtracted, and such a subctraction cannot be performed on c12 due to the even more limited statistics on pi0 events.</div><div><br></div><div>Given this statistical limitation, it is hard to draw any conclusion, or also think of implementing any kind of systematics from this. The BSA on c12 that you see is integrated over the whole part B, and trying to estimate a systematics from it would be a sort of Ansatz, not including possible dependences etc. Furthermore, it would be estimated on a different observable, i.e. the raw asymmetry, instead than on the real, subtracted one.</div><div><br></div><div>Your comment, in any case, pushed us to go back and investigate more throughly the C12 analysis. We found out that due to the limited C12 statistics the BSA is very sensitive to the statistical fluctuation coming from the variation of the exclusivity cuts. In order to be sure that there is no sistematic effects but only a statistical one, we compare the BSA on c12 and on nh3 in the two extreme cases of the exclusivity cuts, i.e. the one corresponding to the 2.5 sigma and the one relative to the 3.5 sigma from the central value of the cut estimated following the procedure described in the analysis note.<br></div><div><br></div><div>At the following links you can see the results relative to these two scenarios:</div><div><br></div><div>2.5 sigma case: <a href="http://www.lnf.infn.it/~pisanos/dvcs/prd/c12/?play=http://www.lnf.infn.it/~pisanos/dvcs/prd/c12/test_bsa_c12_nh3_2.5sigma.png">http://www.lnf.infn.it/~pisanos/dvcs/prd/c12/?play=http://www.lnf.infn.it/~pisanos/dvcs/prd/c12/test_bsa_c12_nh3_2.5sigma.png</a></div><div><br></div><div>3.5 sigma case: <a href="http://www.lnf.infn.it/~pisanos/dvcs/prd/c12/?play=http://www.lnf.infn.it/~pisanos/dvcs/prd/c12/test_bsa_c12_nh3_3.5sigma.png">http://www.lnf.infn.it/~pisanos/dvcs/prd/c12/?play=http://www.lnf.infn.it/~pisanos/dvcs/prd/c12/test_bsa_c12_nh3_3.5sigma.png</a></div><div><br></div><div>together with the results on the fit of the bsa on c12. As you can see, the asymmetry are perfectly compatible, and no shift is observed in the c12 (p0 in the fit box).</div><div><br></div><div>Since these are the two extreme cases and not effects are seen, and being the final contamination - dilution factor - around 8%, we concluded that not further systematics was needed.<br></div><div><br></div><div><div>This said, however, in the systematics studies we did, the one relative to the variation of the exclusivity cuts takes somehow into account possible effects from nuclear background, since, as you can see from Fig. 15, varying the cuts it varies the c12 contamination, and should then include any sensitivity in the BSA emerging from an increased nuclear backgroud.</div><div><br></div></div><div>We realize now that that kind of plots in the final paper could be misleading, and therefore we have decided to remove it and to add a little more explanation in the text. Here is a summary of our reasons to remove the figure:</div><div><br></div><div>1) That figure is supposed to justify why we present the BSA with this data, despite the fact that there is some background from the N14 and therefore it is not the standard free proton BSA. We think that this is not a concern since our background is just 8% and we are applying tight exclusivity cuts which ultimately select N14 protons at quasi-free kinematics;</div><div><br></div><div>2) It would be a concern to have such a background if our results were disagreeing with the BSA measured on free protons (FX et al) but Figure 19 shows that we are consistent;</div><div><br></div><div>3) C12 and in particular C12 BSA is not used anywhere in extracting the results. We only used the total counts of C12 to get the dilution factor.</div><div><br></div><div><br></div><div>As to the minor points, we added our answers below in this mail.</div><div><br></div><div><br></div><div>Thanks again for your interest in our work.</div><div><br></div><div><br></div><div>Best regards,</div><div><br></div><div>Angela, Erin, Silvia N. and Silvia P.</div><div><br></div></div></blockquote>I agree that probably leaving that plot out altogether is the best solution, since it does not “prove” or “clarify” as much as it confuses (at least me). I’m still not convinced that there should be NO (=zero) systematic uncertainty quoted on the BSA from nuclear effects. Clearly, looking at your 3 cases, one could come up with a reasonable range of BSAs for 12C alone (albeit integrated over everything but phi). Then it is a straightforward calculation to see how the average H asymmetry would be changed if you added a 8-10% contamination with that (slightly) different BSA into it. Determine the relative change for all the cases you studied, take the RMS, and you have a simple systematic uncertainty you could quote. (NOTE: I am not insisting on any of this - I’m just trying to help make the paper more compelling. If you disagree, simply ignore it…)</div><div><br><blockquote type="cite"><div dir="ltr"><div><br></div><div><div>-------------------------------------------------------------------------------------------</div><div><br></div><div><br></div><div>- Eq. 1 uses symbols e and e' for lepton 4-momenta. In Line 152 k and k'</div><div>are used, instead. This should be made consistent. Also, in Line 154 and</div><div>Eq. 9, the symbol "epsilon" is used for Q/nu which is unusual (and can be</div><div>confused with the virtual photon polarization, which is not discussed at</div><div>all).</div><div><br></div><div>Corrected the e/e' part (thank you for pointing this out). As far as epsilon, we are adopting the same notation as in the BMK paper (Ref.[10]), we believe it is better to stick to it to avoid confusion, in case the reader goes to cross-check on that article.</div><div><br></div><div>- Line 180 reads a bit like gibberish - I would end the previous line with</div><div>a period and then simply start "It is given, at twist..."</div><div><br></div><div>Thank you for spotting this out. Let us take the blame off the AHC. They did a great and thorough job, maybe this sentence and some other "gibberish" ones came from our very final edition after the last round of comments.</div><div><br></div><div>- Line 319: "the analog", not "analogous"</div><div><br></div><div>Actually, the dictionary says: "analogous: adjective</div><div>1. having analogy; corresponding in some particular"</div><div>We believe that both analog and analogous are acceptable.</div><div><br></div></div></div></blockquote>No they’re not ;-) - as you quote from the dictionary: “analogous is an ADJECTIVE” which would have to be followed by a noun - or at least not preceded by an article like “the”</div><div><br><blockquote type="cite"><div dir="ltr"><div><div>- Fig. 11, 4th line of the caption: At the end, you probably mean "shaded</div><div>areas", not plots.</div><div><br></div><div>OK, fixed, thank you.</div><div><br></div><div>- Line 573: "Numerator" and "Denominator" should be switched</div><div><br></div><div>No, here we refer to "c" not to Df. And if you look at the definition of "c" (from Peter Bosted), it has NH3 in the numerator and C12 in the denominator.</div></div></div></blockquote><div><br></div>Ah, yes. I guess if I was confused, others MIGHT be as well - the ideal solution would be to add a simple equation like “c = tau(NH3)/tau(12C)” or whatever you want to call the areal densities. Again, totally up to you...<br><blockquote type="cite"><div dir="ltr"><div><div><br></div><div>- Lines 584-5: "a constant fit is doable" sounds a bit sloppy. What you</div><div>mean is that within errors a constant can be fit?</div><div><br></div><div>OK, sentence modified.</div><div><br></div><div>- Line 631: "beside each quantity" -> "of each quantity"</div><div><br></div><div>OK.</div><div>- Line 726 reads a bit awkward</div><div><br></div><div>Not sure in what way it is awkward, but we modified it a bit anyway.</div><div><br></div><div>- Line 739 remove "their" at the end</div><div><br></div><div>OK.</div><div><br></div><div>- In Sec.V.10, you don't really explain the model you use for ALT at all</div><div><br></div><div>We say at line 758: "using the GPD model VGG [24] (described in Section VI)." Section VI has the description of the model. What else do you think is missing?</div></div></div></blockquote><div><br></div>The sentence starting at line 757 only refers to AUT(0) (and the next one, as well). So it reads as if the model only applies to that quantity. If it ALSO predicts ALT(0), this should simply be added (at the very top of p. 14, column 2): “for AUT and ALT” or some such.<br><blockquote type="cite"><div dir="ltr"><div><div><br></div><div>- Line 787 at the end "is of ORDER approx 4%"</div><div><br></div><div>Fixed, by removing "of".</div><div><br></div><div>- Line 808 and other places: replace "in average" with "on average" (do a</div><div>global search and replace)</div><div><br></div><div>OK, done.</div><div><br></div><div>- Line 851: "Precisely, the.." you probably mean something like "In</div><div>detail,..."</div><div><br></div><div>What about "Specifically”?</div></div></div></blockquote><div><br></div>Fine by me<br><blockquote type="cite"><div dir="ltr"><div><div><br></div><div>- Line 979 "closer" -> "closest"</div><div><br></div><div>OK.</div><div><br></div><div>- Line 1054 "...could mix with..." (leave out "up")</div><div><br></div><div>OK.</div><div><br></div><div>- Line 1109 "In recent years" (leave out "the")</div><div><br></div><div>OK.</div><div><br></div><div>- You should reference Table V in the text, probably right at the beginning</div><div>of Section VII</div><div><br></div><div>It is already referenced in Sections V.10 and is Section VII.</div><div><br></div><div><br></div><div>---------------------------------------------------------------------------------------------------------</div><div><br></div><div>Thanks again for your help.</div></div></div></blockquote><div><br></div>Merry Christmas / Buon Natale!<br><blockquote type="cite"><div dir="ltr"><div><br></div><div><br></div>-- <br><div class="gmail_signature"> "Life was just chemistry, <br> and chemistry was just physics." - Jonah Lehrer<div><br></div><div><div>*********************************************************</div><div>Dott.ssa Silvia Pisano</div><div>Laboratori Nazionali di Fisica Nucleare - Frascati</div><div>Office: +39 0694032325</div><div>Cell.: +39 3290617328</div><div>Blog: <a href="http://tanticapricci.blogspot.com/" target="_blank">http://tanticapricci.blogspot.com/</a></div></div></div>
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