= Gregory Breit
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{tag=Physicist}
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<Gregory Breit> and <Eugene Wigner> explained strong variations in slow-<neutron> capture through resonant nuclear excitation. In modern notation, an isolated <nuclear resonance> has a contribution proportional to $\Gamma_n\Gamma_\gamma/[(E-E_r)^2+\Gamma^2/4]$, apart from spin and kinematic factors. Here $\Gamma_n$ and $\Gamma_\gamma$ describe the entrance and radiative channels, while $\Gamma$ is the total <decay width>. With slowly varying prefactors, moving $\Gamma/2$ to either side of $E_r$ halves the peak, connecting its observed width with the unstable intermediate state.<Capture of Slow Neutrons by Gregory Breit and Eugene Wigner>[1936 paper, resonant capture and radiative damping; modern isolated-resonance notation and half-height calculation]{ref}
\Image[https://commons.wikimedia.org/wiki/Special:Redirect/file/Gregory_Breit.jpg?width=249]
{title=Portrait of <Gregory Breit>}
{description=From the National Academy of Sciences biographical memoir of Gregory Breit; photographer not identified on Commons. https://commons.wikimedia.org/wiki/File:Gregory_Breit.jpg#Licensing[Attribution-only permission stated on the Commons file page], via Wikimedia Commons.}
{source=https://commons.wikimedia.org/wiki/File:Gregory_Breit.jpg}
{width=249}
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