Interacting boson model

The interacting boson model (IBM) is a model in nuclear physics in whichnucleons (protons or neutrons) pair up, essentiallyacting as a single particle with boson properties, withintegral spin of 0, 2 or 4. The interacting boson model (IBM) is a model in nuclear physics in whichnucleons (protons or neutrons) pair up, essentiallyacting as a single particle with boson properties, withintegral spin of 0, 2 or 4. It is sometimes known as the Interacting boson approximation (IBA).:7 The IBM1/IBM-I model treats both types of nucleons the same and considers only pairs of nucleons coupled tototal angular momentum 0 and 2, called respectively, s and d bosons. The IBM2/IBM-II model treats protons and neutrons separately. Both models are restricted to nuclei with even numbers of protons and neutrons.:9 The model can be used to predict vibrational and rotational modes of non-spherical nuclei. This model was invented by Akito Arima and Francesco Iachello in 1974.:6