{"id":3624,"date":"2011-04-13T21:20:56","date_gmt":"2011-04-14T01:20:56","guid":{"rendered":"http:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=3624"},"modified":"2011-04-18T20:23:23","modified_gmt":"2011-04-19T00:23:23","slug":"no-wimps","status":"publish","type":"post","link":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=3624","title":{"rendered":"No WIMPs"},"content":{"rendered":"<p>A <a href=\"http:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=3611&#038;cpage=1#comment-86731\">commenter<\/a> points to the long-awaited release of a <a href=\"http:\/\/arxiv.org\/abs\/1104.2549\">preprint<\/a> from the XENON100 experiment giving results from a 100-day run last year.  This is the most sensitive dark matter experiment that has released data.  The result:  with an expected background of 1.8 +\/- .6 events, they see 3 events (i.e. about what you&#8217;d expect if there&#8217;s nothing there).  For a WIMP mass of 50 GeV, this allows them to exclude certain WIMP cross-sections at the level of 7.0 x 10<sup>-45<\/sup>cm<sup>2<\/sup>.  This pretty conclusively kills off some other claims by dark matter experiments to have seen something, especially the CDMS result from late 2009 (see <a href=\"http:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=2597\">here<\/a>).<\/p>\n<p>One motivation for supersymmetry has always been that it can provide a WIMP with the right properties to explain astrophysical dark matter observations.  This new data rules out some (if you use the SUSY expectations plotted in the new paper), or most (if you use the expectations plotted in the <a href=\"http:\/\/www.sciencemag.org\/content\/327\/5973\/1619.full\">CDMS paper<\/a>, see <a href=\"http:\/\/dorigo.wordpress.com\/2008\/03\/05\/susy-more-unlikely-by-the-new-cdms-ii-results\/\">here<\/a> and <a href=\"http:\/\/blogs.discovermagazine.com\/cosmicvariance\/2008\/02\/27\/whats-the-dark-matter\/\">here<\/a>)  of the possible parameter space where such a particle is expected, providing yet another nail in the SUSY coffin. <\/p>\n<p><strong>Update<\/strong>:  More details available at <a href=\"http:\/\/resonaances.blogspot.com\/2011\/04\/xenon100-nothing.html\">Resonaances<\/a> and <a href=\"http:\/\/www.science20.com\/quantum_diaries_survivor\/new_xenon_100_results_dark_matter-78134\">Tommaso Dorigo&#8217;s blog<\/a>.<\/p>\n<p><strong>Update<\/strong>:  For a detailed analysis of the implications of the XENON100 result for supersymmetry models, see <a href=\"http:\/\/arxiv.org\/abs\/1104.3572\">here<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A commenter points to the long-awaited release of a preprint from the XENON100 experiment giving results from a 100-day run last year. This is the most sensitive dark matter experiment that has released data. The result: with an expected background &hellip; <a href=\"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=3624\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[9],"tags":[],"class_list":["post-3624","post","type-post","status-publish","format-standard","hentry","category-experimental-hep-news"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3624","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3624"}],"version-history":[{"count":9,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3624\/revisions"}],"predecessor-version":[{"id":3642,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/3624\/revisions\/3642"}],"wp:attachment":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3624"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3624"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3624"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}