Saturday, 8 March 2014

Weekend Plot: all of dark matter

To put my recent posts into a bigger perspective, here's a graph summarizing all of dark matter particles discovered so far via direct or indirect detection:

The graph shows the number of years the signal has survived vs. the inferred mass of the dark matter particle. The particle names follow the usual Particle Data Group conventions. The label's size is related to the statistical significance of the signal. The colors correspond to the Bayesian likelihood that the signal originates from dark matter, from uncertain (red) to very unlikely (blue). The masses of the discovered particles span impressive 11 orders of magnitude, although the largest concentration is near the weak scale (this is called the WIMP miracle). If I forgot any particle for which a compelling evidence exists, let me know, and I will add it to the graph.

Here are the original references for the Bulbulon, BoehmotCollaron, CDMesonDaemon, CresstonHooperon, Wenigon, Pamelon, and the mother of Bert and Ernie

15 comments:

ronval912 said...

on the colors: red more or less likely than green?

Robert L. Oldershaw said...

Waiting for the Godot particle?

Simon Fiorucci said...

You could perhaps also add the CDMS-Si candidate, reported here: http://arxiv.org/abs/1304.4279

Not sure what the proper nomenclature would be. CDMeson?

Jester said...

Thanks, CDMeson added. Ronval, red is uncertain, green is dubious.

Luboš Motl said...

LOL, good names, and quite a "consensus".

Anonymous said...

How about this?

http://arxiv.org/abs/arXiv:1309.3790

Marni Sheppeard said...

LOL, yeah. Perhaps if we remove all the 'indirect' results wrt WIMP type interpretations?

Jester said...

Anon, let's say the evidence must exist in more than one mind for the particle to make it into my plot :) Otherwise the plot would be too crowded.

Anonymous said...

If a paper has multiple authors, by what rule did you pick the author who gets the honour of naming the particle?

Jester said...

The one who has most self-citations of the discovery paper.

Alex said...

Since dark matter is the hot topic for this blog at the moment, any comment on these?
http://arxiv.org/abs/1403.1365
http://arxiv.org/abs/1402.6950

I know that MOND papers aren't really particle physics, per se, but anything that decreases the likelihood of MOND increases the Bayesian likelihood that some dark matter search will eventually find something.

andrew said...

Given the LUX exclusions and the Bohemont's uncanny three significant digit coincidence with the rest mass of an electron, as well as astronomy data's distaste for cold dark matter relative to warm dark matter, I'm gong to have to say that the "Bulbulon", despite being a newcomer, it the most plausible of the lot.

FWIW, I first suspected that all of the names were from Sesame Street, particularly given the Hooperon. Impressive that they are not.

Ben said...

What do you mean by "Bayesian likelihood"? Do you mean your own estimated (posterior) probability?

Alex said...

Yeah, basically a posterior probability. I was typing off-the-cuff. If I want to estimate the probability that a signal is due to dark matter depends, I need to ask how likely it is that dark matter exists at all.

If I wanted to ask the probability that some gamma rays from whatever region of space are due to cupcake-powered gamma ray generators, I'd have to estimate (among other things) the probability that cupcake-powered machines exist in that region of space. If that's a low-probability hypothesis, the fact that the signal would be perfectly consistent with such a machine is largely irrelevant. OTOH, if I wanted to ask about the probability that a messy living room is the result of a cupcake-powered toddler running around, we know that cupcakes and toddlers exist on earth, and we know that kids can get hyper from too much sugar, so now I have to ask whether there's evidence that a toddler was in the vicinity of that living room recently.

andrew said...

"they find a best-fit value of the scalar-tensor ratio of r = 0.20 +0.07/-0.05"

Yes, I can read rumors.