Comments on: About the DAMA-LIBRA result

By: No CHAMPS in CDF data « A Quantum Diaries Survivor

No CHAMPS in CDF data « A Quantum Diaries Survivor — Mon, 12 Jan 2009 17:27:44 +0000

[...] detector we cook up unscathed. Despite that, we of course are looking for such things, with CDMS, DAMA, and other dark-matter-dedicated [...]

By: Guest Post: Juan Collar on Dark Matter Detection | Cosmic Variance | Discover Magazine

Wed, 31 Dec 2008 01:01:38 +0000

[...] may have heard some of the buzz about a new result concerning the direct detection of dark matter particles in an underground [...]

By: Arkani-Hamed: “Dark Forces, Smoking Guns, and Lepton Jets at the LHC” « A Quantum Diaries Survivor

Sun, 21 Dec 2008 12:01:21 +0000

[...] the cosmological inputs have difficulty with the standard WIMP scenario. DAMA, Pamela, Atic are recently evidenced anomalies that do not fit with our simplest-minded picture. [...]

By: Highlights from the morning talks at PPC08 « A Quantum Diaries Survivor

Highlights from the morning talks at PPC08 « A Quantum Diaries Survivor — Mon, 19 May 2008 19:30:34 +0000

[...] about the “Latest results from the DAMA-LIBRA collaboration“. I discussed these results in a post about a month ago, and Riccardo did not show anything I had not already seen, although his [...]

By: dorigo

dorigo — Mon, 28 Apr 2008 21:09:23 +0000

Uncle Al, your proposal would be interesting to submit. Maybe the US congress would get excited about it… I know many would vote to fund it just to see what happens.

Cheers,
T.

By: And I thought I had been harsh… « A Quantum Diaries Survivor

And I thought I had been harsh… « A Quantum Diaries Survivor — Mon, 21 Apr 2008 15:16:36 +0000

[...] and – I still thank Sean for linking to my own commentary of the DAMA-LIBRA [...]

By: Guest Post: Juan Collar on Dark Matter Detection | Cosmic Variance

Guest Post: Juan Collar on Dark Matter Detection | Cosmic Variance — Mon, 21 Apr 2008 14:50:55 +0000

[...] may have heard some of the buzz about a new result concerning the direct detection of dark matter particles in an underground [...]

By: Uncle Al

Uncle Al — Sun, 20 Apr 2008 21:32:43 +0000

Collar, JI, et al., Science 319(5865) 933 (2007)
“Spin-Dependent WIMP Limits from a Bubble Chamber”
(no WIMPs)

Sensitivity, selectivity, modest cost, and active medium Enviro-whiner hissy fit CF3I. Results from large scale apparatus using perfluorobutane will be flat out exciting.

Like 100,000 gallons of perchloroethylene buried 4900 feet deep, Collar’s setup lacks the looming visceral thrill of accidently dropping a hex nut and blasting South Dakota into space. Uncle Al recommends a Media darling active medium: iodine heptafluoride, IF7.

CF3I,
bp -32.5°C, d = 2.36 g/ml
@ 25°C, d = 2.06 g/ml liquid
29.092 wt-% F, 64.777 wt-% I

IF7,
mp = 4.5 C d = 2.7 g/cm^3 (solid)
bp = 4.77 C, colorless
51.171 wt-% F, 48.829 wt-% I

Incompatible with Pyrex, fused silica (Teflon AF windows?), and most metals (Monel?); expensive, corrosive, toxic, malodorous. IF7 has it all!

By: World of Science News : Blog Archive : links for 2008-04-20 [Uncertain Principles]

Sun, 20 Apr 2008 11:02:33 +0000

[...] About the DAMA-LIBRA result « A Quantum Diaries Survivor A closer look at a controversial claim to have detected dark matter (tags: physics astronomy science blogs experiment theory) Read the comments on this post… [...]

By: dorigo

dorigo — Fri, 18 Apr 2008 15:10:59 +0000

Hi Erik,

indeed, as I noted in #12, there are ways to confirm the galactic origin of the signal. I think the check you propose has been done already by DAMA-LIBRA, but the one that Carlo Rubbia suggested today at the conference of course hasn’t yet…

Cheers,
T.

By: dorigo

dorigo — Fri, 18 Apr 2008 15:09:51 +0000

Hi DB,

yes – the general feeling is that one cannot dismiss this result, but take it seriously and try to verify it with an independent experiment. Rubbia today suggested to take the whole apparatus to the southern emisphere and re-do the experiment – the logic being that a galactic signal would not change sign while a seasonal one would. We will see what happens.

Cheers,
T.

By: DB

DB — Fri, 18 Apr 2008 15:03:42 +0000

T.,
New Scientist issued a report on this yesterday; the massive scepticism which greeted DAMA’s previous announcements over the last eight years still seems to linger, but the tone seems to have moderated:

http://space.newscientist.com/article/dn13726-dark-matter-may-have-been-found-on-earth.html

By: Erik

Erik — Fri, 18 Apr 2008 10:04:44 +0000

Thinking a bit more.. Comparing plots from both 24h and 23.934h windows could discriminate very nicely between solar and galactic origin.

By: Erik

Erik — Fri, 18 Apr 2008 09:43:23 +0000

Couldn’t radiation originating from the sun have a similar modulation? Neutrinos coming through the earth would have different angles at summer and winter. I could not find if there was any 24h modulation, have they made such a plot?

By: dorigo

dorigo — Fri, 18 Apr 2008 07:56:30 +0000

Hi Lubos,

no, as far as I know I am not Russian (but one can never be completely sure). In any case, thank you, fixed – It is a mistake I tend to repeat, along with a few others.

Cheers,
T.

By: Luboš Motl

Luboš Motl — Fri, 18 Apr 2008 07:24:24 +0000

Dear Tommaso, “symmetry” is spelled with “y”, not with “i”, unless you are Russian.

By: Kea

Kea — Thu, 17 Apr 2008 22:43:26 +0000

Very interesting post, thanks. I think the ball is in both the theorists and experimentalists’ courts. Firstly, surely the experiment needs to be duplicated by an independent group. Secondly, I wouldn’t put any money on any of the standard DM candidates, so it is clear that theorists have a lot of work to do.

By: dorigo

dorigo — Thu, 17 Apr 2008 20:05:10 +0000

Hi Changcho,

if you have these intuition often, please let me know the next time… Sometimes it would save me time to know what I’d be writing about later

No, I am not too convinced. The signal is genuine, but I have reasons for concern. The main weakness of the experiment is that whatever they find they cannot determine what it is…

Cheers,
T.

By: changcho

changcho — Thu, 17 Apr 2008 19:27:35 +0000

I knew you’d write something about this. I first read about this from CIP’s blog (http://capitalistimperialistpig.blogspot.com): something about italian particle particle physicists finding possible evidence for WIMPs). So, you don’t sound too convinced?

By: dorigo

dorigo — Thu, 17 Apr 2008 18:20:28 +0000

Hi Nick, welcome!

This blog is for people like you, who like to read about physics. I try to keep this blog to a level lower than yours, but you will find a lot of information here.

Cheers,
T.