{"id":2091,"date":"2007-12-18T12:58:48","date_gmt":"2007-12-18T12:58:48","guid":{"rendered":"http:\/\/scienceblogs.com\/principles\/2007\/12\/18\/lazy-particle-physics-query\/"},"modified":"2007-12-18T12:58:48","modified_gmt":"2007-12-18T12:58:48","slug":"lazy-particle-physics-query","status":"publish","type":"post","link":"http:\/\/chadorzel.com\/principles\/2007\/12\/18\/lazy-particle-physics-query\/","title":{"rendered":"Lazy Particle Physics Query"},"content":{"rendered":"

I could probably tease this information out of the Particle Data Group<\/a> website, given enough time, but somebody with a background in particle physics can probably answer this in two seconds, so I appeal to the Internets:<\/p>\n

\n

What is the shortest lifetime of a particle that has been directly detected?<\/p>\n<\/blockquote>\n

By “directly detected” I mean, well, directly detected. Something that has been identified from a track in a detector, or a click in a calorimeter, and not something whose existence has been inferred from a resonance observed in the production of other things.<\/p>\n

My half-assed guess would be a neutral pion, with a lifetime on the order of 10-16<\/sup>s, but I could easily be wrong. So what’s the right answer?<\/p>\n

<\/p>\n

(This is a factoid to be dropped in a discussion of “virtual particles” in my book. I could just as easily skip it, but it ocurred to me as something to throw in, so if I can get the answer, I’ll use it…)<\/p>\n

(The “neutral pion” guess is because I know that pions were discovered relatively early, and I know that the neutral pion has a really short lifetime. I’m not sure about the detection history, though.)<\/p>\n","protected":false},"excerpt":{"rendered":"

I could probably tease this information out of the Particle Data Group website, given enough time, but somebody with a background in particle physics can probably answer this in two seconds, so I appeal to the Internets: What is the shortest lifetime of a particle that has been directly detected? By “directly detected” I mean,… Continue reading Lazy Particle Physics Query<\/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-2091","post","type-post","status-publish","format-standard","hentry","category-experiment","entry"],"_links":{"self":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/2091","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=2091"}],"version-history":[{"count":0,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/2091\/revisions"}],"wp:attachment":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/media?parent=2091"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/categories?post=2091"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/tags?post=2091"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}