QUESTION #117

Since there are such things as anti-electrons and anti-protons, is there such a thing as an anti-neutron?

Asked by: Howie Soucek

Answer

In a word: Yes. According to the standard model, every fundamental particle, has a corresponding antiparticle. for example, the antiparticle of the electron is the positron (short for 'positive electron'). However, protons and neutrons are not themselves fundamental particles; they are composed of smaller particles called quarks. A proton contains two up quarks and one down quark (uud), and a neutron contains one up and two down quarks (udd). the up quark has a charge of +2/3 and the down quark has a charge of -1/3. If you add up the charges in the proton and neutron, you will find they are the observed values. Therefore the anti-proton has two anti-up quarks and one anti-down quark (each of which having the same charge with opposite sign) giving it a total charge of -1. The antineutron contains one anti-up quark and two ant-down quarks, giving it a charge of 0, just like the regular neutron.
Answered by: Bill Zaientz, 12th Grade Student