parity in nuclear physics.
Parity of a nucleus refers to the behaviour of the wave function(¥) under inversion of coordinates. e.g if we replace x by -x, y by -y and z by -z and wave function remains the same, then it has even parity. On other hand, if it appears with negative sign, it has odd parity as shown below ¥(x,y,z)=¥(-x,-y,-z) even parity ¥(x,y,z)= - ¥(-x,-y,-z) Odd parity