| Abbreviation | Definition |
|---|---|
| PAC | Probably Approximately Correct |
| PAES | Positron-Induced Auger Electron Spectroscopy |
| PAIS | Photo Acoustic Infrared Spectroscopy |
| PAR | Partially Absorbed or Reflected |
| PASS | Particle Accelerator Security System |
| PASU | Physics Astronomy Students Union |
| PAU | Physics of the Accelerating Universe |
| PAW | Physics Analysis Workstation |
| PAW | Physics Analysis Workstationpaw |
| PB | Parabolic Barrier |
| PB | Plackett Burman |
| PB | Primary Beam |
| PB | Property Bivalence |
| PBC | Polarization Beam Combiner |
| PBCS | Physics of Biological and Complex Systems |
| PBE | Pool Boiling Experiment |
| PBG | Photonic Band Gap |
| PBO | Particle Beam Optics |
| PBQ | PhotoBeam Quantum |
| PBR | Physics Based Rendering |