tag:blogger.com,1999:blog-2846514233477399562.post5579001077266201785..comments2024-01-08T09:37:04.406+01:00Comments on RÉSONAANCES: Xenon100: NothingJesterhttp://www.blogger.com/profile/08947218566941608850noreply@blogger.comBlogger12125tag:blogger.com,1999:blog-2846514233477399562.post-76267005135383273312011-04-20T13:55:57.047+01:002011-04-20T13:55:57.047+01:00Hi Jester - I think Davoudiasl is consistent with ...Hi Jester - I think Davoudiasl is consistent with 0011335. Note that if you look at the plots, the characteristic cross section when normalizing relic abundance is typically ~10^-45 or a bit lower for heavier WIMPs and MH=O(120). But, I agree, it's a funny way of writing the cross section because the coupling is characteristically smaller than O(1) to DM.<br /><br />The way I think about it (which is certainly a feeble approximation) is that Z's have O(1) couplings to matter, while the effective Higgs Yukawa is ~1/3 x mp/v ~ 10^-3 (where the 1/3 is uncertain and comes from people who know how to calculate such things). So if Z's give ~10^-39, I expect Higgses to give (10^-3)^2 x 10^-39 ~ 10^-45. That's obviously super hand-wavy but from my perspective we're just now getting into what I think of as the rich part of the "Higgs-mediated" region for thermal WIMPs.NWhttps://www.blogger.com/profile/02649443893492970948noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-50426791154252083082011-04-19T01:36:23.014+01:002011-04-19T01:36:23.014+01:00Alejandro, only if you predict zombie superpartner...Alejandro, only if you predict zombie superpartners.Keahttps://www.blogger.com/profile/05652514294703722285noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-70480872098331273642011-04-18T08:31:32.318+01:002011-04-18T08:31:32.318+01:00Kea, do you include my version of susy between the...Kea, do you include my version of susy between the zoombie stringy ones?Alejandro Riverohttps://www.blogger.com/profile/16181521111080562335noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-82364943229453230682011-04-17T10:54:03.011+01:002011-04-17T10:54:03.011+01:00There is no large under/overdensity in the DM halo...There is no large under/overdensity in the DM halo, according to formation with the CDM paradigm with newtonian gravity: the halo turns out to be quite smooth (there are also experimental constraints from stellar kinematics.) The local density can then be estimated as 0.4+-0.2 GeV/cm3 (at 1 sigma!). Ref is <a href="http://inspirebeta.net/record/849062" rel="nofollow">http://inspirebeta.net/record/849062</a>Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-27723851126862530282011-04-15T20:43:09.107+01:002011-04-15T20:43:09.107+01:00@NW: Concerning the Higgs exchange, for example he...@NW: Concerning the Higgs exchange, for example hep-ph/0011335 quotes σ ~(DM-Higgs coupling)^2*(120 GeV/mh)^4*(100 GeV/mDM)^2*10^-42cm2 . Davoudiasl et al must be using a smaller coupling, but I can't figure out what exactly they put in.Jesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-50747606998411688152011-04-15T18:12:52.161+01:002011-04-15T18:12:52.161+01:00Maybe the dark halo is very different to the stand...Maybe the dark halo is very different to the standard one. See http://arxiv.org/abs/1103.6091: a WIMP with mass in the TeV range and a rotating dark disk could be a viable solution for DAMA and the recoils measured by the other experiments.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-72002548022550447672011-04-15T07:52:23.419+01:002011-04-15T07:52:23.419+01:00"It is statistically improbable for us to be ..."It is statistically improbable for us to be in a region of abnormally"<br /><br />anthropic principle to the rescue ^_^chrisnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-8083196601148708492011-04-15T01:48:47.755+01:002011-04-15T01:48:47.755+01:00It is statistically improbable for us to be in a r...It is statistically improbable for us to be in a region of abnormally low dark matter density. It seems cowardly to invoke particles with arbitrarily low cross section. The whole thing starts to feel like aether - something that absolutely ought to be there, but aint. And it can get even worse - http://physics.aps.org/articles/v4/23Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-11700846534220073002011-04-14T19:47:30.071+01:002011-04-14T19:47:30.071+01:00The poor zombie stringy susy just keeps on going r...The poor zombie stringy susy just keeps on going regardless, heh? What we need now is a susy reduction combination plot for multiple experiments: LHC, Xenon, etc.Keahttps://www.blogger.com/profile/05652514294703722285noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-24346207138775502702011-04-14T18:56:11.692+01:002011-04-14T18:56:11.692+01:00Of course there's always the possibility that ...Of course there's always the possibility that we are living in a region of low dark matter density inside the halo. <br />This is always a possibility to revive your favorite weak scale dark matter model.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-6211205954723410332011-04-14T18:33:52.981+01:002011-04-14T18:33:52.981+01:00I meant per nucleon...indeed I screwed with Z. I&#...I meant per nucleon...indeed I screwed with Z. I'll doublecheck the Higgs...Jesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-87986286275445415082011-04-14T17:45:39.123+01:002011-04-14T17:45:39.123+01:00Jester - are you talking about cross section, or c...Jester - are you talking about cross section, or cross section per nucleon? The cross section per nucleon for a Z-boson is I think around 10^-39 (see Essig 0710.1668 eq 1) and for a Higgs boson I think it's more like 10^-45 (ish) see e.g., Davoudiasl et al 0405097 fig 2. So I think the region we're about to get into is the Higgs mediated region.NWhttps://www.blogger.com/profile/02649443893492970948noreply@blogger.com