{"id":641,"date":"2006-09-26T09:42:11","date_gmt":"2006-09-26T09:42:11","guid":{"rendered":"http:\/\/scienceblogs.com\/principles\/2006\/09\/26\/counting-leptons\/"},"modified":"2006-09-26T09:42:11","modified_gmt":"2006-09-26T09:42:11","slug":"counting-leptons","status":"publish","type":"post","link":"http:\/\/chadorzel.com\/principles\/2006\/09\/26\/counting-leptons\/","title":{"rendered":"Counting Leptons"},"content":{"rendered":"<p>Quantum Diaries survivor Tommaso Dorigo <a href=\"http:\/\/dorigo.wordpress.com\/2006\/09\/25\/a-suspicious-excess-of-same-sign-lepton-pairs\/\">offers an inside look at experimental particle physics<\/a>, describing new results from combing through CDF data to look for rare events producing two leptons with the same charge:<\/p>\n<blockquote>\n<p>Indeed, 44 events were found when 33.7 were expected, plus or minus 3.5. That corresponds to a roughly 2-sigma fluctuation of expected counts. The picture on the left shows the leading lepton spectrum for the 44 events in the signal region.<\/p>\n<\/blockquote>\n<p>What he leaves out is that this is 44 events out of a total number that&#8217;s almost certainly in the millions. Particle physicists are sort of inured to this, and rarely have the total size of the dataset to hand, but I find it absolutely fascinating. The events that reveal interesting physics are such a vanishingly small fraction of the data that they collect that it&#8217;s just amazing that we ever learn anything. And yet, they&#8217;ve done amazing things in particle physics over the years.<\/p>\n<p>The particular particle excess he&#8217;s describing probably doesn&#8217;t mean anything (two-sigma deviations are a dime a dozen), and Tommaso has bet money that they don&#8217;t mean anything, but it&#8217;s a fascinating look at how particle physicists work.<\/p>\n<p>(Which reminds me, I really ought to Classic Edition my old posts about the pentaquark&#8230;)<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Quantum Diaries survivor Tommaso Dorigo offers an inside look at experimental particle physics, describing new results from combing through CDF data to look for rare events producing two leptons with the same charge: Indeed, 44 events were found when 33.7 were expected, plus or minus 3.5. That corresponds to a roughly 2-sigma fluctuation of expected&hellip; <a class=\"more-link\" href=\"http:\/\/chadorzel.com\/principles\/2006\/09\/26\/counting-leptons\/\">Continue reading <span class=\"screen-reader-text\">Counting Leptons<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"1","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19],"tags":[],"class_list":["post-641","post","type-post","status-publish","format-standard","hentry","category-experiment","entry"],"_links":{"self":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/641","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/comments?post=641"}],"version-history":[{"count":0,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/641\/revisions"}],"wp:attachment":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/media?parent=641"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/categories?post=641"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/tags?post=641"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}