RSVP home

About MECO


KOPIO Who's Who
KOPIO @ Brookhaven

The Heart of Matter
Constituents of Matter
Symmetry Violaton
Measuring B(KOPIO)

Project participants

Science in the National Interest

Brookhaven home

The KOPIO Experiment

The physicists who designed KOPIO are looking for a very rare reaction with the potential to explain the observed lack of symmetry between matter and anti-matter in the universe.

We know that the Universe “prefers” matter over antimatter, even though these mirror-image particles once appeared to follow perfectly symmetrical laws of physics. If the laws governing matter and antimatter were symmetrical, we would not have a Universe. Why did the Big Bang produce matter instead of an even 50/50 mixture of matter and antimatter?

The KOPIO Experimental apparatus (particle beam enters from left).

The answer may lie in the discovery of a new asymmetry of nature, evidence that an antimatter universe, a mirror image of our own, would not behave in precisely the same way. Using the AGS proton accelerator at Brookhaven National Laboratory, the KOPIO experimenters wish to create an intense beam of kaons to study special very rare decays (viz. a kaon decaying into a neutral pion, a neutrino, and an antineutrino). The discovery and observation of these rare reactions will incisively probe charge parity (CP) symmetry violation, fundamental evidence that a mirror-image anti-universe would look slightly different from our own. This is important because the laws of physics are incomplete without the ability to explain the observed large-scale matter/antimatter asymmetry of the universe which is intimately related to subtleties that distinguish the behavior of matter from that of antimatter.

Read more in "KOPIO – A New Investigation into the Heart of Matter", a technical discussion of the experiment.


Last updated January 24, 2006 by Gary Schroeder.