Universe Today
[/caption] Scientists from the PAMELA (Payload for Antimatter/Matter Exploration and Light-nuclei Astrophysics) orbiting spacecraft have published preliminary results, putting an end to months of speculation about the first direct detection of dark matter. The science team was, in essence, "forced" to publish before they had conclusive results because other scientists "pirated" data from the team. "We wanted to make our final results available to the scientific community once the data analysis was finalised," PAMELA member Mirko Boezio said in an article in
Physicsworld.com.
"Given that our preliminary conference data are starting to be used by people, we felt this was a necessary step — not least because it provides a proper reference that correctly acknowledges the whole PAMELA collaboration and is available to the scientific community at large." This is not the way the PAMELA team wanted to present their results, but really, they had no choice.
In a preprint on
arXiv,
the team says PAMELA has seen more positrons above a certain energy (10GeV) than can be explained by known physics. This excess seems to match what dark matter particles would produce if they were annihilating each other at the center of the galaxy. This excess, the authors say, "may constitute the first indirect evidence of dark-matter particle annihilations." But they add that there could yet be other explanations, such as that positrons of this kind of energy can also be generated by nearby pulsars.
The science team will need to gather more data and do more work to be able to distinguish between the positron signature of dark matter annihilation and the positron signature of pulsars.
Two previous papers were published based
on photos taken of slides of preliminary data that were shown at a science conference by the PAMELA team. See their papers
here
and
here.
We humans are a curious and impatient lot. But we have to allow scientists to do their job, and do it the best way that science allows. Science done right does not mean secrecy or concealment. It means not speculating and waiting to announce results until proof positive. A similar event happened earlier this year with the Phoenix team and the detection of perchlorates. The Phoenix science team was forced to call a press conference to end all the speculation. Right now, the PAMELA team cannot say conclusively one way or the other whether they've made a direct detection of dark matter. Given enough time and more data, they will. Unless someone else steals the show again.
Sources:
Physicsworld
,
arXiv
,
arXiv blog
