<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Dear Michael,<div class=""><br class=""></div><div class="">Yes, this is what I originally suggested for the experimentally determined sums over all events.</div><div class=""><br class=""></div><div class="">In the meantime, I think I need to revise the expressions and the numerator sum should read: <b class="">cos(\alpha)</b> and the denominator sum should read <b class="">Q cos^2(\alpha)</b>. This and the earlier expressions give the same results for constant background or if the observable does not change over the kinematic bin; like in our simplified examples. Practically, the differences will be small. However, when there are variations of the observable or of the background over a large bin (like in the double-pion case), the latter expressions give in my opinion results for the observable which are more meaningful.</div><div class=""><br class=""></div><div class="">I will update my slides and we can discuss this more during tomorrow’s meeting.</div><div class=""><br class=""></div><div class="">Steffen</div><div class=""><br class=""></div><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Aug 17, 2016, at 1:21 PM, Michael Dugger <<a href="mailto:dugger@jlab.org" class="">dugger@jlab.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><br class="">Steffen,<br class=""><br class="">I just want to make sure I understand.<br class=""><br class="">You weight each numerator event by<br class=""><br class="">Q cos(\alpha)<br class=""><br class="">and each denominator event by<br class=""><br class="">[Q cos(\alpha)]^2 .<br class=""><br class="">Is this correct?<br class=""><br class="">Take care,<br class="">Michael<br class=""><br class="">On Wed, 17 Aug 2016, Steffen Strauch wrote:<br class=""><br class=""><blockquote type="cite" class="">Dear Michael,<br class=""><br class="">It is important that the weights in the moments in the denominator contain an additional factor of Q compared to the numerator.<br class=""><br class="">I don’t think there is a typo here. If you compare on page 4 the two sets of moment ratios, you see that the first set already contains Q in the integral. Weighing the cos(alpha) moment with an additional factor of Q, gives you the Q^2 in the integral of the numerator in the second set. The denominator of the first set does not contain any Q in the integral. So, an additional factor of Q^2 in the weight of the moment gives you the Q^2 in the integral of the denominator of the second set.<br class=""><br class="">For the correct expression that the extracted value is the weighted average of P and not Q*P.<br class=""><br class="">Thanks,<br class="">Steffen<br class=""><br class=""><br class=""><br class=""><blockquote type="cite" class="">On Aug 17, 2016, at 12:06 PM, Michael Dugger <<a href="mailto:dugger@jlab.org" class="">dugger@jlab.org</a>> wrote:<br class=""><br class=""><br class="">Steffen,<br class=""><br class="">On last line of slide 4 and slide 5 of your pdf:<br class=""><br class=""><a href="https://www.jlab.org/Hall-B/secure/g9/g9_strauch/mtg/FROST_meeting_2016_08_18.pdf" class="">https://www.jlab.org/Hall-B/secure/g9/g9_strauch/mtg/FROST_meeting_2016_08_18.pdf</a><br class=""><br class="">you show on the left hand side<br class=""><br class="">Y_{Q cos\alpha}/Y_{Q^2 cos^2 \alpha},<br class=""><br class="">where there is a factor of Q in the numerator and a factor of Q^2 in the denominator.<br class=""><br class="">However, in the middle of the line you have Q^2 in both the numerator and denominator. Is there a typo?<br class=""><br class="">If you have Q^2 in both the numerator and denominator, the expression will not work.<br class=""><br class="">Take care,<br class="">Michael<br class="">_______________________________________________<br class="">Frost mailing list<br class="">Frost@jlab.org<br class="">https://mailman.jlab.org/mailman/listinfo/frost<br class=""></blockquote><br class=""></blockquote>_______________________________________________<br class="">Frost mailing list<br class=""><a href="mailto:Frost@jlab.org" class="">Frost@jlab.org</a><br class="">https://mailman.jlab.org/mailman/listinfo/frost</div></blockquote></div><br class=""></div></body></html>