Interacting boson model

The interacting boson model (IBM) is a model in nuclear physics in which nucleons (protons or neutrons) pair up, essentially acting as a single particle with boson properties, with integral spin of 0, 2 or 4.

It is sometimes known as the Interacting boson approximation (IBA).

The IBM1/IBM-I model treats both types of nucleons the same and considers only pairs of nucleons coupled to total 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.

Regions of differently shaped nuclei, as predicted by the Interacting Boson Approximation

The model can be used to predict vibrational and rotational modes of non-spherical nuclei.

History

This model was invented by Akito Arima and Francesco Iachello in 1974.

See also

• Liquid drop model
• Nuclear shell model

References

• Arima, Iachello Collective nuclear states as representations of a SU(6) Group, Physical Review Letters 35, 1069–1072 (1975).
• Arima, Iachello The interacting boson model, Cambridge University Press, 1987.
• Arima, Iachello Interacting boson model of collective states, Part 1 (the vibrational limit) Annals of Physics 99, 253-317 (1976), Part 2 (the rotational limit) ibid. 111, 201-238 (1978), Part 3 (the transition from SU (5) to SU (3)), ibid. 115, 325-366 (1978), Part 4 (the O(6) limit) ibid. 123, 468-492 (1979).
• Arima, Iachello The Interacting Boson Model, Annual Review of Nuclear and Particle Science 31, 75 (1981).
• Talmi Simple Models of Complex Nuclei: The Shell Model and the Interacting Boson Model (1993) Harwood Academic Publishers

Further reading

• Evolution of shapes in even–even nuclei using the standard interacting boson model