Pion Constituents: Nucleon & Antinucleon Explained

[ruchika]

The nucleon and antinucleon are each about seven times more massive than the pion How is it conceivable that the pion could be a combination of nucleon and antinucleon

 

[Norman]

You are exactly correct, the pion is not made up of a nucleon and an antinucleon. The pion is a meson and is composed of a quark and an antiquark. In the case of a pion, it is made up of up and down (anti)quarks. Whether it is a positive, negative or neutral (electric) charged pion determines whether the up or down (or a linear combination) is quark or antiquark.

You should consider picking up Griffiths "Introduction to Elementary Particles." It is an excellent book.

 

[humanino]

What is conceivable, is to describe the nucleon as a chiral soliton in a pionic field, where the scalar and pseudoscalar Goldstone meson are treated as if elementary. Please note that this is a (convenient, powerful, elegant, appealing ?) model which neither ignores its own approximations (those fields are not fundamental) nor can not be at least partially justified from a more fundamental point of view. In particular, it attempts to treat spontaneous chiral symmetry breaking effectively.