Summary
Scientists have discovered semi-Dirac fermions, particles that bizarrely gain or lose mass depending on the direction they travel.
Found in the semi-metal material ZrSiS, these quasiparticles are massless when moving at light speed in one direction but gain mass when slowing down in another, due to resistance within the material’s electronic structure.
This behavior, tied to Einstein’s E=mc², was unexpected and may lead to applications similar to graphene.
Researchers are now studying the unexplained quantum interactions behind this phenomenon, published in Physical Review X.
Sounds more like a property of the material than the particle.
Edit: did a little reading. It’s not even a real particle, it’s a quasi-particle, which apparently means it’s a general description of a group of particles.
That’s even crazier
I think a quasi-particle is more like a phenomenon that can mathematically be described in a way a particle would be, rather than just a group of particles. After all, holes in semiconductors are quasiparticles caused by a lack of real particles.
Admittedly, I know very little about quasi-particles.