The 1964 symmetry-breaking mechanism was discovered independently by three groups, but only Higgs's papers explicitly predicted a massive scalar particle

physicshistory-of-sciencehiggs-bosonpriority-disputemultiple-discoverycredit-assignmentCERN

John Ellis's historical account states that spontaneous breaking of gauge symmetry entered particle physics in 1964 three times over: François Englert and Robert Brout published first, showing a non-Abelian Yang-Mills gauge boson could acquire mass via spontaneous symmetry breaking; Peter Higgs followed independently — unaware of the Englert-Brout paper — with two papers, the first evading Walter Gilbert's earlier no-go theorem (that Lorentz invariance forbids avoiding a massless Goldstone boson via gauge symmetry), the second demonstrating mass generation explicitly in the Abelian case; Gerald Guralnik, C. R. Hagen, and Tom Kibble published afterward, citing both prior pairs. Of the three papers, only Higgs's second one notes — via its equation (2b) — the existence of an associated massive scalar particle, the "Higgs boson." Englert and Brout's paper does not discuss the physical scalar spectrum; the Guralnik-Hagen-Kibble model instead contains a massless, decoupled scalar.

This is a textbook instance of the vault's standing thesis that multiple independent discovery is science's dominant pattern — compare reverse-mode differentiation's five-fold independent discovery — but with an added wrinkle Merton's framework doesn't fully explain: the physical content (vector-boson mass from broken symmetry, which is what the mechanism actually is) was multiply discovered, while one specific downstream prediction — the massive scalar — was a Higgs-only addition that later became the mechanism's popular, metonymic name. The paper's own title, "the EBH mechanism" rather than "the Higgs mechanism," is Ellis quietly arguing the credit split should track the mechanism's substance, not its most famous particle.