Looking at the

fundamental particles.They are all pretty damn small. The

photon is near the bottom of the list, listed as having a "Mass" of <1×10

^{−18} eV/c

^{2}The

Gluon is listed with a "Mass" of < 0.0002 eV/c

^{2} (of course, it is defining a range, and not an exact value).

The

Electron Nutrino is listed as the mass simply being "Small but non-zero".

So, do we know the photon is the smallest particle discovered so far?