# Higgs, Peter (Ware)

### mass field gravitational particle

(1929–) British cosmologist and particle physicist: devised the ‘Higgs field’ theory.

Educated at Bristol, London and Edinburgh, Higgs taught and researched in Edinburgh from 1960 and became professor of theoretical physics there in 1980.

The concept of mass is complex. In classical physics, the mass of a body is a measure of its inertia, its reluctance to undergo a change of velocity. In this sense, mass can be defined operationally as the ratio of the magnitudes of the force *F* and the acceleration *a* it produces in a body of mass *m* ; so *m* = *F* / *a* . This definition, due to , was later used by who recognized also that this ‘inertial’ mass is apparently universally proportional both to the active gravitational mass of the body (the measure of the gravitational field it produces) and to its passive gravitational mass (the measure of the gravitational pull exerted on it by other bodies). work embraced mass in his theory of relativity, which assumed the identity of inertial and gravitational mass and also showed that a mass *m* is related to the energy *E* involved in its destruction or generation by *E* = *mc* 2 .

The elementary particles from which matter is made have masses over a large range, from the light electron to the heavier W and Z particles and the top quark. It is not obvious why particles, and therefore matter, should possess mass at all. In this context, a theory due to Higgs provides a possible explanation. The theory proposes that all space is permeated by a field (the Higgs field) which has some similarity to an electromagnetic field. A particle moving through this field, and interacting with it, will appear to have mass; and the greater the interaction the larger the mass.

In general a field has a particle associated with it; the electromagnetic field is associated with the photon (which has no mass). Analogously, the Higgs field may be linked with a particle (the Higgs boson, believed to be heavy) or possibly with more than one particle. Proof or disproof of the existence of such a particle and other aspects of the theory would be of the highest value in theoretical physics. It would illuminate the nature of mass and gravitational attraction and perhaps link the latter with the other known physical forces (electromagnetic force, and the strong and weak nuclear forces).

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