# Can a neutron be created from pure energy

Is it possible to create a neutron out of pure energy, i.e. not by bringing a bunch of already-existing quarks together? (A quick calculation using E = mc2 shows the energy required would be about 1.5 e-10 J.)

Would an equivalent antiparticle always need to be created?

• If you want to create a single neutron then the answer is no. To create a neutron antineutron pair is certainly possible. – Fabian Sep 19 '12 at 22:01
• BTW, a particle physicsist would say that the energy is needed is a bit less than 2 GeV (for the pair which is as @Fabiansay is necessary), which are much more convenient units for this kind of discussio – dmckee --- ex-moderator kitten Sep 20 '12 at 0:12
• Related - Energy of the electron-muon reaction – voix Sep 20 '12 at 4:43

For example: $n \to e^+ e^- \bar{\nu}_e \to \gamma \;\gamma\;\bar{\nu}_e$