{"id":2931,"date":"2010-05-04T09:54:15","date_gmt":"2010-05-04T13:54:15","guid":{"rendered":"http:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=2931"},"modified":"2010-05-06T12:03:04","modified_gmt":"2010-05-06T16:03:04","slug":"first-results-from-xenon100","status":"publish","type":"post","link":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=2931","title":{"rendered":"First Results From XENON100"},"content":{"rendered":"<p>The XENON100 dark matter experiment now has a <a href=\"http:\/\/arxiv.org\/abs\/1005.0380\">paper<\/a> out reporting their first results, from a test run of 11 days.  They claim a 90% confidence level exclusion of 50 GeV WIMPs with a spin-independent elastic cross-section above 3 x 10<sup>-44<\/sup> cm<sup>2<\/sup>, which one can compare with the <a href=\"http:\/\/arxiv.org\/abs\/0912.3592\">recent CDMS limit<\/a> of 3.8 x 10<sup>-44<\/sup> cm<sup>2<\/sup> at similar mass (70 GeV).  At the time of the CDMS result many seemed to believe that the two events seen were not background (see <a href=\"http:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=2597\">here<\/a>), with Gordon Kane claiming &#8220;it is likely it is dark matter.&#8221;  The New York Times has an <a href=\"http:\/\/www.nytimes.com\/2010\/05\/04\/science\/space\/04dark.html\">article<\/a> today, with Kane now commenting on XENON100 &#8220;if they see a signal, it will be unambiguous&#8221;, by which I presume he means that their full data will conclusively show whether the CDMS events could have been a signal.   Given that they are seeing nothing at all now, at 10 times greater sensitivity later, they may very well see an ambiguous signal&#8230;<\/p>\n<p>The XENON100 result also appears to rule out claims from the DAMA and CoGeNT experiments to have seen some sort of signal.  For more on this, as always in dark matter issues, <a href=\"http:\/\/resonaances.blogspot.com\/2010\/05\/more-dark-entries.html\">Resonaances<\/a> has the best coverage of the story. <\/p>\n<p><strong>Update<\/strong>:  <a href=\"http:\/\/physicsworld.com\/cws\/article\/news\/42554\">Physics World<\/a> reports on objections to the XENON100 claims from a CoGeNT physicist and others, see this <a href=\"http:\/\/arxiv.org\/abs\/1005.0838\">arXiv preprint<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The XENON100 dark matter experiment now has a paper out reporting their first results, from a test run of 11 days. They claim a 90% confidence level exclusion of 50 GeV WIMPs with a spin-independent elastic cross-section above 3 x &hellip; <a href=\"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=2931\">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-2931","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\/2931","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=2931"}],"version-history":[{"count":8,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2931\/revisions"}],"predecessor-version":[{"id":2937,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2931\/revisions\/2937"}],"wp:attachment":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2931"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2931"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2931"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}