<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi Bradley,<div class=""><br class=""></div><div class="">That is great investigative work. You should now indeed check the other EGS5 generators for similar issues. As we discussed yesterday, there may be an issue with the background events for tridents.</div><div class=""><br class=""></div><div class="">Can you please mention (advertise) this new result at the analysis meeting today?</div><div class=""><br class=""></div><div class="">Best,</div><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>Maurik</div><div class=""><br class=""></div><div class=""><br class=""><div class=""><div><blockquote type="cite" class=""><div class="">On May 13, 2016, at 3:25 AM, Bradley T Yale <<a href="mailto:btu29@wildcats.unh.edu" class="">btu29@wildcats.unh.edu</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div id="divtagdefaultwrapper" style="font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; font-size: 12pt; background-color: rgb(255, 255, 255); font-family: Calibri, Arial, Helvetica, sans-serif;" class=""><div style="margin-top: 0px; margin-bottom: 0px;" class="">I think I found the real problem with how the Moller generator was initially set up.<br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class="">This one affects the generated distribution a LOT more than the RNG precision probably did, and explains the remaining strangeness in the generated distribution.<br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class="">Looking at the egs5 Moller procedure, the angular cut was defined as:<br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class="">abs(v(np)) > 0.010 radians<span class="Apple-converted-space"> </span><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class="">where v(np) is supposed to be theta.</div><div style="margin-top: 0px; margin-bottom: 0px;" class="">However, the variables u, v, and w in egs are actually<span class="Apple-converted-space"> </span><b class="">directional cosines</b>, p_x = p*u, p_y = p*v, and p_z = p*w.<br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class=""><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class="">So this means that in reality, the generator was saving Moller events such that</div><div style="margin-top: 0px; margin-bottom: 0px;" class="">abs [ sin(theta)*sin(phi) ] > 0.010<br class=""></div><div id="Signature" class=""><div id="divtagdefaultwrapper" style="font-size: 12pt; background-color: rgb(255, 255, 255); font-family: Calibri, Arial, Helvetica, sans-serif;" class=""><div style="margin-top: 0px; margin-bottom: 0px;" class=""><br class=""></div><div style="margin-top: 0px; margin-bottom: 0px;" class="">which has a periodic nature to it. Plot this equation for some value of phi (or just think about it) and you'll see what was likely making these strange hills and gaps in the energy distribution - full-wave rectified Mollers!</div><br class="">The scattered beam simulation does correctly define theta though:<br class="">sqrt[ u^2 + v^2 ]<br class=""><br class="">I made a moller_v3 procedure with this correction (still with a >10 mrad cut), and the comparison between before and after is shown.<br class="">The generated events now agree with the calculated cross section (XS curve is shown on the 'bad' plot), and no apparent missing events.<br class=""><br class="">These will be run through recon to see if we can finally get good Moller agreement with data.<br class="">I'm also going to try changing the scattered beam energy cut shown in the software meeting to see if it fixes Tim's phi vs. energy discrepancy.<br class="">-Brad<br class=""></div></div></div><span id="cid:3BDA2E4A-4C4E-4713-BBE4-A9A6403A9DC1@hsd1.me.comcast.net"><BadMollers.png></span><span id="cid:9CEC52F1-9615-4C34-9DB9-42ADE75FE9BC@hsd1.me.comcast.net"><2pt3_mol_v3_moller_E.png></span><span style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">_______________________________________________</span><br style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><span style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">Hps-analysis mailing list</span><br style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><a href="mailto:Hps-analysis@jlab.org" style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">Hps-analysis@jlab.org</a><br style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><a href="https://mailman.jlab.org/mailman/listinfo/hps-analysis" style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">https://mailman.jlab.org/mailman/listinfo/hps-analysis</a></div></blockquote></div><br class=""></div></div></body></html>