{"id":210,"date":"2008-12-02T04:31:31","date_gmt":"2008-12-02T04:31:31","guid":{"rendered":"http:\/\/spinor.info\/weblog\/?p=210"},"modified":"2008-12-02T04:31:31","modified_gmt":"2008-12-02T04:31:31","slug":"anomalous-positrons-a-smoking-gun-for-dark-matter","status":"publish","type":"post","link":"https:\/\/spinor.info\/weblog\/?p=210","title":{"rendered":"Anomalous positrons: a smoking gun for dark matter?"},"content":{"rendered":"<p>In recent weeks, there has been a lot of discussion in the physics community about a curious observation: an <a href=\"http:\/\/arxiv.org\/abs\/0810.4995\">abundance of energetic positrons<\/a> observed by a satellite named PAMELA. According to some people, this unexpected abundance of positrons is likely caused by annihilation of massive dark matter particles, constituting &#8220;smoking gun&#8221; evidence that dark matter really exists.<\/p>\n<p>Of course it is possible that this abundance is due to some conventional astrophysics, such as pulsars doing this or that. This is a subject of on-going dispute.<\/p>\n<p>One thing I do not see discussed is that the anticipated behavior is apparently based on <a href=\"http:\/\/arxiv.org\/abs\/astro-ph\/9710124\">a model<\/a> developed several years ago that uses as many as eleven adjustable parameters yet nevertheless, does not produce a spectacularly good fit of even the low energy data. I wonder if I am missing something.<\/p>\n<div id=\"attachment_214\" style=\"width: 310px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/spinor.info\/weblog\/wp-content\/uploads\/2008\/12\/pamela.gif\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-214\" class=\"size-medium wp-image-214\" title=\"PAMELA positron fraction and theoretical models.\" src=\"http:\/\/spinor.info\/weblog\/wp-content\/uploads\/2008\/12\/pamela.gif\" alt=\"PAMELA positron fraction and theoretical models.\" width=\"300\" height=\"283\" \/><\/a><p id=\"caption-attachment-214\" class=\"wp-caption-text\">PAMELA positron fraction and theoretical models.<\/p><\/div>\n<fb:like href='https:\/\/spinor.info\/weblog\/?p=210' send='true' layout='standard' show_faces='true' width='450' height='65' action='like' colorscheme='light' font='lucida grande'><\/fb:like>","protected":false},"excerpt":{"rendered":"<p>In recent weeks, there has been a lot of discussion in the physics community about a curious observation: an abundance of energetic positrons observed by a satellite named PAMELA. According to some people, this unexpected abundance of positrons is likely caused by annihilation of massive dark matter particles, constituting &#8220;smoking gun&#8221; evidence that dark matter <a href='https:\/\/spinor.info\/weblog\/?p=210' class='excerpt-more'>[&#8230;]<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-210","post","type-post","status-publish","format-standard","hentry","category-physics","category-3-id","post-seq-1","post-parity-odd","meta-position-corners","fix"],"_links":{"self":[{"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=\/wp\/v2\/posts\/210","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=210"}],"version-history":[{"count":6,"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=\/wp\/v2\/posts\/210\/revisions"}],"predecessor-version":[{"id":217,"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=\/wp\/v2\/posts\/210\/revisions\/217"}],"wp:attachment":[{"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=210"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=210"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spinor.info\/weblog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=210"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}