Petaelectronvolt

Petaelectronvolt, abbreviated PeV, is a unit of energy used in high-energy physics. One PeV equals 10^15 electronvolts (eV), which is about 1.6 × 10^-4 joules. The electronvolt is the energy gained by an elementary charge moving through one volt; the prefix peta- denotes 10^15. PeV is a convenient scale for describing extremely energetic particles such as cosmic rays and neutrinos.

In laboratory settings, particle accelerators typically reach the TeV (teraelectronvolt) scale; current colliders like the Large Hadron Collider operate at several TeV per beam, corresponding to tens of TeV in center-of-mass energy. PeV energies are not achieved in existing terrestrial accelerators and are more commonly discussed in astrophysics. The term PeVatron is used for hypothesized astrophysical sources capable of accelerating particles to PeV energies, potentially located in supernova remnants, active galactic nuclei, or pulsar wind nebulae.

Observationally, PeV-scale phenomena include neutrinos detected with energies near or above 1 PeV by the IceCube Neutrino Observatory, providing evidence for astrophysical particle acceleration. PeV gamma rays are sought with ground-based detectors, though their travel is affected by interactions with radiation fields. The cosmic ray spectrum exhibits a feature near a few PeV called the knee, related to a transition in the dominant acceleration or propagation mechanism. PeV physics thus sits at the high-energy frontier of both terrestrial and space-based observations.