Resonance (particle physics)

The
ϒ
(1S) resonance, as observed by the E288 collaboration, headed by Leon Lederman, at Fermilab in 1977. The resonance is located at 9.5 GeV, corresponding to the mass of the
ϒ
(1S).

In particle physics, a resonance is the peak located around a certain energy found in differential cross sections of scattering experiments. These peaks are associated with subatomic particles (such as Nucleons, Delta baryons, Upsilon mesons, tauons, ...) and their excitations. The width of the resonance (Γ) is related to the lifetime (τ) of the particle (or its excited state) by the relation

$\Gamma ={\frac {\hbar }{\tau }}$

where ħ is the planck constant.

See also

• Subatomic particles
• Resonance width