Do massless fermions exist in modern physics?

[LarryS]

Does modern physics allow for the existence of massless fermions?

 

[PeterDonis]

Sure. In the Standard Model, all the fundamental fermions are massless; they only acquire mass through their interaction with the Higgs boson.

 

[atyy]

In graphene, there are emergent particles at low energies whose behaviour is well described by a theory of massless fermions. http://arxiv.org/abs/cond-mat/0509330