IEVref: 113-03-04 ID: Language: en Status: Standard Term: rest mass Synonym1: proper mass [Preferred] Synonym2: Synonym3: Symbol: m0 Definition: for a particle, its mass in an inertial frame where that particle has zero speedNOTE 1 When the speed of the particle is negligible compared to the speed of light, the difference between mass and rest mass is also negligible. NOTE 2 The rest mass of particle X is denoted $m\left(\text{X)}$ or mX; for example me denotes the mass of electron. Publication date: 2011-04 Source: Replaces: Internal notes: 2017-06-02: Cleanup - Remove Attached Image 113-03-04en.gif CO remarks: TC/SC remarks: VT remarks: Domain1: Domain2: Domain3: Domain4: Domain5: