Wednesday, April 03, 2013

AMS Confirms Excess Positrons

Hope you guys were following the announcement today.

In any case, APS has released the paper on the latest result from AMS, reporting and confirming earlier reports on the excess positrons measurement. You can get acess to the PRL paper for free from the link. What does this all mean?

There has been no shortage of speculation about what might cause the positron “excess” above 10GeV. One idea is that relatively nearby cosmic bodies, such as pulsars, act as accelerators and colliders that produce antimatter, much like our terrestrial Large Hadron Collider. But a more exciting possibility is that the positrons come from the annihilation of dark matter particles, which may populate the Milky Way and its halo. Dark matter is, after all, a dominant form of the matter-energy budget of the Universe, but we don’t know its particle nature or how it interacts with itself and with normal matter (other than through gravitational interactions). It is no overstatement to say that identifying the dark matter is one of the greatest problems in modern science.
A lot of work remains to be done, but unlike the search for Supersymmetric particles, there are experimental indications that are consistent with Dark Matter models.


1 comment:

cb said...

May be it is safer to say the announcement of first results from AMS-02 ends on a genune cliffhanger regarding dark matter !
Physicists may hesitate between statistical flukes (bumps in the energy spectrum of positron fraction, coming from pulsars?) and a statistical cliff (at high energy: the smoking gun signal of dark matter)...