Orbiting observatory finds dark matter, but what kind?


The world of cosmology is abuzz with rumours that an orbiting observatory called PAMELA has discovered dark matter. Last month, the PAMELA team gave a few selected physicists a sneak preview of their results at a conference in Stockholm.

Here’s the deal. The PAMELA people  say their experiment has seen more positrons than can be explained by known physics and that this excess exactly matches what dark matter particles would produce if they were annihilating each other at the center of the galaxy.

What makes this particularly exciting is that other orbiting observatories have also seen similar, but less clear cut, evidence of dark matter annihilations.

Since then, the shutters have come down. With the prospect of a major discovery on their hands  and with publication in a major journal at stake, the team has closed ranks to re-analyse their data and prepare it for exclusive publication. Not a word has leaked from the PAMELA team since their preliminary announcement.

That hasn’t stopped physicists speculating for themselves. Today Marco Cirelli from the CEA near Paris in France and Alessandro Strumia from the Università di Pisa in Italy present their own analysis of the PAMELA data.

Cosmologists have long speculated on the nature of dark matter and dreamt up all manner of models and particles to explain it. The big question is which type of particle does the PAMELA data point towards.

Today, Cirelli and Strumia stake their own claim. They say the data agrees with their own model called Minimal Dark Matter in which the particle responsible is called the “Wino” (no, it  really is called the wino).

But given the PAMELA team’s reluctance to publish just yet, where did Cirelli and Strumia get the data? The answer is buried in a footnote in their paper.

“The preliminary data points for positron and antiproton fluxes plotted in our figures have been extracted from a photo of the slides taken during the talk, and can thereby slightly differ from the data that the PAMELA collaboration will officially publish.”

Can’t fault them for initiative.

Ref: arxiv.org/abs/0808.3867: Minimal Dark Matter Predictions and the PAMELA Positron Excess

31 Responses to “Orbiting observatory finds dark matter, but what kind?”

  1. dr. dave says:

    Keep in mind that the “wino” is the supersymmetric partner to the W boson. It is not pronounced like the word for a homeless alcoholic. Physicists typically pronounce it “weeeeno” or “doubleyou-eeno”.

  2. [...] are indications that an orbiting experiment called PAMELA is finding an excess positron signal consistent with expectatio….

  3. hanzie says:

    well, mabye it USED to be pronounced ‘weeno’, but its ‘Y-no’ now ypu might as well give up might as well change now. otherwise you’re going to waste lots of time and explanations an still not convince anyone that you’re anything but a pronounciation snob. anyway, calling an impossible to see particle a wino just seems right.

  4. Lula says:

    I think we should go the Philip Pullman route and call them “shadows” or “Dust.”

  5. Francis says:

    Presumed sentiments of the PAMELA team: Pereant qui ante nos nostra dixerunt: To the devil with those who published before us. — Aelius Donatus

  6. Ralf says:

    As usual, the correct pronunciation will distinguish the people in the know from the wannabees. Just like Linux (’Lee-nux or maybe ‘Lynn-ux but not ‘Lie-nux) for example.
    Fascinating stuff, that. About time the Standard Model got an overhaul. It’s been fraying at the edges for some time.

  7. dr. dave says:

    Sure, while we’re at it, we’ll give the ok for “NOOK-YOU-LAR”

    (I won’t deny being a pronunciation snob, but i will deny the “nothing but”. I happen to have a PhD in theoretical particle physics.)

  8. jim says:

    FYI, the Italian pronunciation for both words is “weeno”. The suffix “ino” means “little” in Italian.

  9. heh says:

    Heh. I’ve got a PhD in theo particle physics, too, and my advisor would regularly walk in the office to ask how my nuk-u-lar studies were coming, and whether I’d found any athen-icle partners to my sparticles.

  10. Ralf says:

    P.S. I miss the WIMPs vs MACHOs arguments – there’s just a better ring to that than wino. Looks like the WIMPs have won and maybe they’re SUSY WIMPs.

  11. If you can find the matter, it isn’t really dark anymore, is it?

  12. Stonan says:

    7 responses and over half are about linguistics?!? Come on people, some of you are scientists! I doubt any of you are English Majors…

  13. bevil says:

    thats what happens when u get posted on slashdot

  14. kiwi says:

    “Cell phones with cams are banned during all meeting proceedings”
    Expect this in your coming conference :)

  15. [...] Como siempre, según se desarrolle esta noticia los mantendremos informados acá en eliax. Fuente de la noticia Previamente en eliax: Astrónomos creen tener prueba de “Materia Oscura” (Agosto 2006) Hubble [...]

  16. dadidiehard says:

    OK guys…c’mon I didn’t even finish high school so stop wasting my time and teach me something about dark matter!

  17. alfredo says:

    The first thing you need to understand about dark matter is…finish high school.

  18. Hassan Bin Sober says:

    Did they run out of names for this stuff? The only real WINO’s (residentialy challenged citizens) used to camp out and sip inexpensive Muscatell from paper bags at the corner of 3rd & Howard (the wine country)in San Francisco in the 1950’s.

  19. Remain skeptical. Cirelli and Strumia see their own model in the data from a slide.

    At this time, I do not accept the dark matter hypothesis. We do have a problem with every large scale momentum profile involving gravity. I think that is the sign of a math problem.

  20. Marco Cirelli says:

    where did you see that our proposed Dark Matter candidate is called “wino”? It is not. “Wino” (the partner of the W boson in SuperSymmetry, as someone has already said) is one of the possible candidates of SuperSymmetry (loosely speaking).
    Our particle does not have a particular name: the theoretical construction is called Minimal Dark Matter, so if you want you can call it this way. In one of the previous papers we say that one of our candidates “has the same quantum numbers as the Wino”. This is done just to connect to the usual lingo of SuperSymmetry, but does not mean anything. This might be the source of the confusion.

    Also: we did not “see our model in a slide” and went crazy. Yes, we love our pet model, but the predictions for what PAMELA should have seen were there before in our paper arXiv:0802.3378. The only thing we did was to compare to the data once they came out. We found agreement.

    Marco (marco.cirelli@cea.fr)

  21. [...] observatory finds dark matter, but what kind? the physics arXiv blog

  22. Rick Shaffer says:

    Alas, I only have a B. S. in Physics, but I gotta say it: You ARE a pronunciation snob, and so am I! Whenever I heard the last prez who was also a scientist totally mangle the word “neclear” as “nukear”, it was as if the entire world were scraping its collective finger nails across a blackboard!

    At least the “Pinhead-in-Chief” has an excuse!

  23. Px says:

    The most interesting thing is Pamela’s result.
    These wino models (built up in a week…), like a lot of neutralino, sneutrino or Kaluz-Klain particle models, are nothing new…

  24. [...] Nou, is dat geen knap staaltje van rioolwetenschap? Cirelli en Strumia hebben een geheel eigen variant van DM, de zogenaamde Minimale Donkere Materie, en volgens hun passen de PAMELA-gegevens daar uitstekend in. Het door hun voorgestelde deeltje waaruit de DM zou bestaan noemen ze een wino. Tsja een wino, ik verzin het niet zelf. Jullie begrijpen dat het PAMELA-team niet blij is met de hele gebeurtenis en ik neem ook aan dat het allemaal nog een staartje zal krijgen. Gisteren stond er een klein stukje in NRC-Handelsblad over het gebeuren en daarin wordt heel toepasselijk gesproken over Paparazzifysici. Wordt vervolgd! Bron: NRC-Handelsblad, 6 september 2008 + ArXiv Blog. [...]

  25. [...] even physicists are writing about this like it’s already a great discovery. They don’t see the anti-protons, folks! That’s not [...]

  26. Mircus says:

    dear Marco, thank you for the clarifications. But why did you choose such a silly name “wino” for your silly Dark Matter model?

  27. Marcus Cohen says:

    Dark matter is not composed of particles- but rather of the “primaeval soup” from which they all condensed. Invariance says that this SPINFLUID has 8 spinors (needed to make a 4 form). This model gives the right families and masses for the Particles (see my papers in arxiv)

  28. Alexander Nahhas says:

    Fraud Kind!

    Say No to Incompetence and Fraud Say No to:
    MIT Harvard Cal-Tech Princeton Stanford
    Perimeter institute + All space-time Physics + NASA = 0
    Why Relativity theory is not Physics and why Einstein’s “thought” = 0
    And why LHC burned itself

    Visual Effects and the confusions of “Modern” physics

    r ——— Light sensing of moving objects ——- S
    Actual object—– Light ——— Visual object

    r – ——-cosine (wt) + i sine (wt) – S = r [cosine (wt) + i sine (wt)]
    Newton– Kepler’s time visual effects — Time dependent Newton Wave Equation

    Line of Sight: r cosine wt

    r ——————- r cosine (wt) line of sight light aberrations

    A moving object with velocity v will be visualized by

    light sensing through an angle (wt);w = constant and t= time

    Also, sine wt = v/c; cosine wt = √ [1-sine² (wt)] = √ [1-(v/c) ²]

    A visual object moving with velocity v will be seen as S

    S = r [cosine (wt) + i sine (wt)] = r Exp [i wt]; Exp = Exponential

    S = r [√ [1-(v/c) ²] + ỉ (v/c)] = S x + i S y

    S x = Visual along the line of sight = r [√ [1-(v/c) ²]

    This Equation is special relativity length contraction formula
    And it is just the visual effects caused by light aberrations of a
    moving object along the line of sight.

    In a right angled velocity triangle A B C: Angle A = wt; angle B = 90°; Angle C = 90° -wt
    AB = hypotenuse = c; BC = opposite = v; CA= adjacent = c √ [1-(v/c) ²]

  29. [...] and Philadelphia, sparking a flurry of activity in the physics world. Some enterprising physicists snapped photos of the presentation’s slides and extracted the data to analyze it themselves. In response, [...]

  30. [...] and Philadelphia, sparking a flurry of activity in the physics world. Some enterprising physicists snapped photos of the presentation’s slides and extracted the data to analyze it themselves. In response, [...]

  31. [...] and Philadelphia, sparking a flurry of activity in the physics world. Some enterprising physicists snapped photos of the presentation’s slides and extracted the data to analyze it themselves. In response, [...]