<html><body><div style="font-family: arial,helvetica,sans-serif; font-size: 12pt; color: #000000"><div>If you have already corrected E_beam, than you don't need to inflate uncertainty. If you want to adjust E_beam in the same fitter, than you have to include this uncertainty in the fitter.</div><div><br></div><div data-marker="__SIG_PRE__">-Eugene</div><div><br></div><hr id="zwchr" data-marker="__DIVIDER__"><div data-marker="__HEADERS__"><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;" data-mce-style="border-left: 2px solid #1010FF; margin-left: 5px; padding-left: 5px; color: #000; font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><b>From: </b>"Lei Guo" <leguo@fiu.edu><br><b>To: </b>"Eugene Pasyuk" <pasyuk@jlab.org><br><b>Cc: </b>"Carlos Salgado" <salgado@jlab.org>, "g12@jlab.org g12@jlab.org" <g12@jlab.org><br><b>Sent: </b>Wednesday, February 10, 2016 4:48:21 PM<br><b>Subject: </b>Re: [G12] resolution of tagger in kinematic fitter<br></blockquote></div><div data-marker="__QUOTED_TEXT__"><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;" data-mce-style="border-left: 2px solid #1010FF; margin-left: 5px; padding-left: 5px; color: #000; font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><div>So I think we have consensus in that it is undercounting if we r just using 0.001*E_beam.... Ur point of the mcc energy being different is also consistent with the fact that we had to do a run-by-run e_beam correction. Technically, we probably should use something around 0.002*e_beam in the kinematic fitting. Agree?<br> <br> Sent from my iPhone</div><div><br> On Feb 10, 2016, at 16:35, Eugene Pasyuk <<a href="mailto:pasyuk@jlab.org" target="_blank" data-mce-href="mailto:pasyuk@jlab.org">pasyuk@jlab.org</a>> wrote:<br> <br></div><blockquote><div><div style="font-family: arial,helvetica,sans-serif; font-size: 12pt; color: #000000" data-mce-style="font-family: arial,helvetica,sans-serif; font-size: 12pt; color: #000000;"><div>This would be a double counting for high energy end. The offset form the nominal bin centroid is always less than the a bin width. </div><div>What needs to be adjusted is E_beam. We always had it deviate from what MCC reports by ~0.1-0.2%, and even up to 0.5% occasionally. But this is multiplicative factor and affects all Eg the same way.</div><div><br></div><div>-Eugene</div><div><br></div><hr id="zwchr"><div><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;" data-mce-style="border-left: 2px solid #1010FF; margin-left: 5px; padding-left: 5px; color: #000; font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><b>From: </b>"Lei Guo" <<a href="mailto:leguo@fiu.edu" target="_blank" data-mce-href="mailto:leguo@fiu.edu">leguo@fiu.edu</a>><br> <b>To: </b>"Eugene Pasyuk" <<a href="mailto:pasyuk@jlab.org" target="_blank" data-mce-href="mailto:pasyuk@jlab.org">pasyuk@jlab.org</a>><br> <b>Cc: </b>"Carlos Salgado" <<a href="mailto:salgado@jlab.org" target="_blank" data-mce-href="mailto:salgado@jlab.org">salgado@jlab.org</a>>, "<a href="mailto:g12@jlab.org" target="_blank" data-mce-href="mailto:g12@jlab.org">g12@jlab.org</a> <a href="mailto:g12@jlab.org" target="_blank" data-mce-href="mailto:g12@jlab.org">g12@jlab.org</a>" <<a href="mailto:g12@jlab.org" target="_blank" data-mce-href="mailto:g12@jlab.org">g12@jlab.org</a>><br> <b>Sent: </b>Wednesday, February 10, 2016 4:22:24 PM<br> <b>Subject: </b>Re: [G12] resolution of tagger in kinematic fitter<br></blockquote></div><div><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;" data-mce-style="border-left: 2px solid #1010FF; margin-left: 5px; padding-left: 5px; color: #000; font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><div>I understand that the 2007 paper is about the correction and now the correction gets applied at cooking. However, there is uncertainty to that correction. So on top of the 0.001*e_beam, there should be additional 0.001*e_gamma, for the overall resolution.<br> <br> Sent from my iPhone</div><div><br> On Feb 10, 2016, at 15:52, Eugene Pasyuk <<a href="mailto:pasyuk@jlab.org" target="_blank" data-mce-href="mailto:pasyuk@jlab.org">pasyuk@jlab.org</a>> wrote:<br> <br></div><blockquote><div><div style="font-family: arial,helvetica,sans-serif; font-size: 12pt; color: #000000" data-mce-style="font-family: arial,helvetica,sans-serif; font-size: 12pt; color: #000000;"><div><br></div><div>You are confusing two different things. </div><div>The tagger reconstruction returns the photon energy as a centroid of the E_bin. The bin widths is almost a constant and is ~0.001*E_beam. The beam centroids originally used are coming from the geometry of the tagger hodoscope and magnetic field. </div><div>During g10 and g11 it was discovered that bin centroids are not what we thought due to gravitational sag of the focal plane.</div><div>To determine the deviation from the expected values two methods were used. One is the calibration you refer to, the other using kinematic fit of g11 data. What you see in the tagger calibration paper is the accuracy of the centroid offset from ideal.</div><div>Once this calibration was done we implemented those corrections in the tagger reconstruction. So, in g12 cooked date it is already accounted for. So, this is not and uncertainty but correction.</div><div>What is left is the bin width. The photon energy could be anything E_bin(i)-Ebin_width/2<Eg<E_bin(i)+Ebin_width/2</div><div>The calibration gives us E_bin(i), but effects of the bin width should go in the kinematic fit. Ebin_width ~ Ebeam*0.001 and it is essentially a constant over focal plane. Carlos' note describes how to get the variance assuming uniform energy distribution within E_bin. </div><div><br></div><div>-Eugene</div><div><br></div><hr id="zwchr"><div><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;" data-mce-style="border-left: 2px solid #1010FF; margin-left: 5px; padding-left: 5px; color: #000; font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><b>From: </b>"Lei Guo" <<a href="mailto:lguo@jlab.org" target="_blank" data-mce-href="mailto:lguo@jlab.org">lguo@jlab.org</a>><br> <b>To: </b>"Carlos Salgado" <<a href="mailto:salgado@jlab.org" target="_blank" data-mce-href="mailto:salgado@jlab.org">salgado@jlab.org</a>>, "Eugene Pasyuk" <<a href="mailto:pasyuk@jlab.org" target="_blank" data-mce-href="mailto:pasyuk@jlab.org">pasyuk@jlab.org</a>><br> <b>Cc: </b>"<a href="mailto:g12@jlab.org" target="_blank" data-mce-href="mailto:g12@jlab.org">g12@jlab.org</a> <a href="mailto:g12@jlab.org" target="_blank" data-mce-href="mailto:g12@jlab.org"> g12@jlab.org</a>" <<a href="mailto:g12@jlab.org" target="_blank" data-mce-href="mailto:g12@jlab.org">g12@jlab.org</a>><br> <b>Sent: </b>Wednesday, February 10, 2016 3:01:22 PM<br> <b>Subject: </b>Re: [G12] resolution of tagger in kinematic fitter<br></blockquote></div><div><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;" data-mce-style="border-left: 2px solid #1010FF; margin-left: 5px; padding-left: 5px; color: #000; font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><br class=""><div><blockquote class=""><div class=""><br class=""> The uncertainty in the energy of the photon is 0.001* E_beam (per NIM and Eugene P.)</div></blockquote><div><br class=""></div><div><br class=""></div><div>I copy and pasted from the 2007 tagger energy calibration NIM paper ():</div><div><br class=""></div><div>"In this report, we present the energy calibration of the Hall B bremsstrahlung tagging system at the Thomas Jefferson National Accelerator Facility. The calibration was performed using a magnetic pair spectrometer. The tagged photon energy spectrum was measured in coincidence with <span id="mmlsi26" class="mathmlsrc"><span class="formulatext stixSupport mathImg" title="Click to view the MathML source">e<sup class="">+</sup>e<sup class="">-<span style="font-family: 'Latin Modern Math', MathJax_Main, STIXGeneral, STIXSizeOneSym, 'DejaVu Sans', 'DejaVu Serif', Cambria, 'Cambria Math', 'Lucida Sans Unicode', 'Arial Unicode MS', 'Lucida Grande', OpenSymbol, 'Standard Symbols L', Times, serif;" data-mce-style="font-family: 'Latin Modern Math', MathJax_Main, STIXGeneral, STIXSizeOneSym, 'DejaVu Sans', 'DejaVu Serif', Cambria, 'Cambria Math', 'Lucida Sans Unicode', 'Arial Unicode MS', 'Lucida Grande', OpenSymbol, 'Standard Symbols L', Times, serif;"> </span></sup></span></span>pairs as a function of the pair spectrometer magnetic field. Taking advantage of the internal linearity of the pair spectrometer, the energy of the tagging system was calibrated at the level of <span id="mmlsi27" class="mathmlsrc"><span class="formulatext stixSupport mathImg" title="Click to view the MathML source">±0.1%E<sub class="">γ <span style="font-family: 'Latin Modern Math', MathJax_Main, STIXGeneral, STIXSizeOneSym, 'DejaVu Sans', 'DejaVu Serif', Cambria, 'Cambria Math', 'Lucida Sans Unicode', 'Arial Unicode MS', 'Lucida Grande', OpenSymbol, 'Standard Symbols L', Times, serif;" data-mce-style="font-family: 'Latin Modern Math', MathJax_Main, STIXGeneral, STIXSizeOneSym, 'DejaVu Sans', 'DejaVu Serif', Cambria, 'Cambria Math', 'Lucida Sans Unicode', 'Arial Unicode MS', 'Lucida Grande', OpenSymbol, 'Standard Symbols L', Times, serif;"> . </span></sub></span></span>The absolute energy scale was determined using the <span id="mmlsi28" class="mathmlsrc"> <span class="formulatext stixSupport mathImg" title="Click to view the MathML source">e<sup class="">+</sup>e<sup class="">-</sup></span><span class="mathContainer hidden"><span class="mathCode">e+e-</span></span></span> rate measurements close to the end-point of the photon spectrum. The energy variations across the full tagging range were found to be < 3MeV”</div><div><br class=""></div><div><br class=""></div><div><br class=""></div><br class=""><blockquote class=""><div class="">The hodos were built such that this is true (different widths)<br class=""> <br class=""> Then consider a counter of width (energy) "a" where the (assume) energy distribution is flat: then Variance = sigma^2 = 1/a* int^a_0 E^2 dE = a^2/3<br class=""> <br class=""> Therefore if we distribute the uncertainty over a counter (energy bin) the variance is : sigma^2 = (0.001*E_beam)**2/3<br class=""> <br class=""> =Carlos<br class=""> _______________________________________________<br class=""> G12 mailing list<br class=""> <a href="mailto:G12@jlab.org" class="" target="_blank" data-mce-href="mailto:G12@jlab.org">G12@jlab.org</a><br class=""> <a href="https://urldefense.proofpoint.com/v2/url?u=https-3A__mailman.jlab.org_mailman_listinfo_g12&d=AwMFaQ&c=1QsCMERiq7JOmEnKpsSyjg&r=hHzTZynKAcZP6Z9X2yfO7w&m=PiuHY8u-uXDfqVhqiOlRNHG5wet7mC3FwA6T0TgQw6o&s=t4ElkvwyKE7_HNwh-jzSttu-xdqUGQrlBrh-PUySwL0&e=" target="_blank" data-mce-href="https://urldefense.proofpoint.com/v2/url?u=https-3A__mailman.jlab.org_mailman_listinfo_g12&d=AwMFaQ&c=1QsCMERiq7JOmEnKpsSyjg&r=hHzTZynKAcZP6Z9X2yfO7w&m=PiuHY8u-uXDfqVhqiOlRNHG5wet7mC3FwA6T0TgQw6o&s=t4ElkvwyKE7_HNwh-jzSttu-xdqUGQrlBrh-PUySwL0&e=">https://mailman.jlab.org/mailman/listinfo/g12</a><br class=""></div></blockquote></div><br class=""> <br></blockquote></div></div></div></blockquote><br></blockquote></div></div></div></blockquote><br></blockquote></div></div></body></html>