Minutes from Emily: ====================================== Luminosity Paper - Jan 31 2018, part 3 ====================================== Got here late, so starting at 14:25. Had just finished 6.1 when I arrived. 6.2 ---- Patrick Q: Why would different sides of the detector have different mu dependency? No real answer/discussion of it. Mu scans have been done since this paper, which would have been interesting to see. Section 7: ----------- * BCMH and Track-Counting are best baselines. * Plots may be misleading regarding track-counting because there are a lot of things in the background that we don't fully understand. 7.2: ---- * Afterglow is the most important background (detector glows due to radioactivity which can lead to a skewed luminosity). Different subdetectors have different method of dealing with this. Ends up being a fairly small systematic in the end. Look at empty BCIDs after fill BCIDs to see how the detector behaves in terms of afterglow since it decays away. 7.3: --- * Mu behavior in vdM scans may not be directly applicable in the pile-up regime of physics operations. * Q: What are we going to do in the HL-LHC Maybe compare luminomitors on two different parts of the detector to see how they compare. 7.3.1: ------- Attempting to address how to handle the calibration since the response isn't linear. 7.4: ---- Seems that they have 'engineered' the consistency . LUCID appears to be the least stable of the options. Discussion about last sentence: * What elastic-scattering measurements? Are they mentioning it to cover themselves? Maybe there is a lower uncertainty on those measurements in specific. * Uncertainty of 2.1% for 2015+2016 means we have done a pretty good job of constraining the uncertainty as the center of mass energy and pileup have increased from 2012 (uncertainty 1.9%). **************************************************** Next time: Chargeed particle multiplicty w/ Emily! ****************************************************