Energy resolution of a homogeneous calorimeter

[hipa7]

TL;DR

Energy resolution of a homogeneous calorimeter

Hi

I want to look at the energy resolution of a homogeneous calorimeter, in the literature I found that is given by
σ/E = a ⊕ b/√E ⊕ c/E and I found that the ⊕ means quadratic sum, what does quadratic sum mean?

Thanks
Aaron

 

[mfb]

$\displaystyle a⊕b = \sqrt{a^2+b^2}$
Also known as sum in quadrature.