In physics, a neutral particle is a particle without an electric charge, such as a neutron.
Stable or long-lived neutral particles Long-lived neutral particles provide a challenge in the construction of particle detectors, because they do not interact electromagnetically, except possibly through their magnetic moments. This means that they do not leave tracks of ionized particles or curve in magnetic fields. Examples of such particles include photons, neutrons, and neutrinos.
Other neutral particles
Other neutral particles are very short-lived and decay before they could be detected even if they were charged. They have been observed only indirectly. They include:
Z bosons Dozens of heavy neutral hadrons: Neutral mesons such as the π0 and K0 The neutral Delta baryon (Δ0), and other neutral baryons, such as the Ξ0 and Λ0 In plasma science, atoms and molecules with no net electric charge are commonly referred to as neutral particles or neutrals.
See also Neutral particle oscillation Truly neutral particle
References
K. Nakamura et al. (Particle Data Group), JP G 37, 075021 (2010) and 2011 partial update for the 2012 edition