Dressed particle

{{Short description|A particle together with excitations from other fields}}

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In theoretical physics, the term dressed particle refers to a bare particle together with some excitations of other quantum fields that are physically inseparable from the bare particle. For example, a dressed electron includes the cloud of virtual electron–positron pairs and photons surrounding the original electron.

A further noteworthy example is represented by polaritons{{cite journal |last=Hopfield |first=J. J. |year=1958 |title=Theory of the Contribution of Excitons to the Complex Dielectric Constant of Crystals |journal=Physical Review |volume=112 |issue=5 |pages=1555–1567 |doi=10.1103/PhysRev.112.1555 |bibcode = 1958PhRv..112.1555H }} in solid-state physics, dressed quasiparticles of dipolar excitations in a medium with photons.

In radiobiology, a dressed particle is a bare particle together with its Debye sphere that neutralizes its electric charge.

Dressed particles are also often called clothed particles.