Microsoft Word - ConversationWithChrisQuiggWhatIsParticlePhysics.doc - ConversationWithChrisQuiggWhatIsParticlePhysics.pdf
Well, I can tell you some of the possibilities that excite me.
One that could happen any day is to find a new force of nature
for which the evidence would be a new particle that
is the mediator of that force.
So that could happen in the strong interactions
or in the weakened electromagnetic interactions.
We know how you look at that.
It's one of the first things people do.
And to find a fifth force of nature or a sixth
or seventh, that would be pretty special.
It would change the way we think about the world.
And the way we understand the forces of nature
is that they're all related to symmetries
that we have recognized in experiment.
So that would be a new symmetry.
And we'd try to put that together with the other symmetries.
There are other symmetries that might just come on their own.
So there's a famous one that's occupied many
of my contemporaries for longer than they would like to admit.
And that's a theory called supersymmetry.
It's a really wonderful idea and sort of the maximal kind of symmetry
that you can imagine mathematically that would
relate different kinds of particles, things
like the electrons and the quarks, to the force particles
or particles like them.
No evidence for it in experiment, but it would be really sweet
if it were to happen.
It might give us a path toward incorporating gravitation
with the other forces.
So those are two things.
We hope very much--
so it's not out of the question, it may even
be possible, for us to find candidates for the dark matter in the universe.
In our experiments here, as big as they are, they will never establish--
because the flight path is limited to tens of meters,
they'll never establish that a dark matter
particle has a cosmological lifetime.
But they might give us something that looks like it could be.
And then if we discover it in another way,
in direct detection or indirect detection,
maybe we can put the pieces together and know a little more
about what the whole world is made of.
So those are just a few things that would be extremely exciting.
You could find compositeness of the quarks and leptons.
