# Particles less massive than leptons?

1. Sep 8, 2010

### granpa

People are always smashing particles together with more and more energy searching for and finding more and more massive particles.
Have there been any searches for particles less massive (and therefore larger) than leptons?

2. Sep 8, 2010

### mathman

At present the least massive (non-zero mass) known particles are neutrinos.

Your comment is a little puzzling - why would less massive particles be larger?

3. Sep 8, 2010

4. Sep 8, 2010

### Kevin_Axion

Leptons are elementary particles and I believe that article deals with confinement of many particle systems such as the electron clouds and atomic nuclei/Quark Confinement.

5. Sep 17, 2010

There are tons of people out there doing tons of experiments. Odds say some are looking for said particles. There are some theories about lighter mass particles which are being searched for (graviton, photon, etc.)

6. Sep 17, 2010

### Kevin_Axion

Gravitons and Photons are massless so you can't compare it to a particle like a Neutrino or any other massive particle for that reason. It's like saying what's less least massive known apple? A kiwi, it's unassosciative.

7. Sep 18, 2010

### arivero

$$\lambda= { \hbar \over m c}$$

8. Sep 16, 2011

### Constantin

I thought all elementary particles are point like, and their size is the Plank Length or around there.

9. Sep 16, 2011

### Polyrhythmic

That statement is contradictory. How can something be pointlike and at the same time be characterized by some length?

10. Sep 16, 2011

### Constantin

Because a point in physics is not infinitely small.
Plank length is the shortest measurable length.

11. Sep 16, 2011

### Hootenanny

Staff Emeritus
Whilst the latter statement may be true, the former isn't. A point is a point. The notion of a "point" in physics is not distinct from topological notion of a point.

12. Sep 16, 2011

### Polyrhythmic

If a point is not infinitely small (zero dimensional), it's by definition not a point.