$\delta$${\pt}$ of random cones in the 10% most central Pb--Pb events for the three types of random cone probes with
${p_{\rm t}^{\rm min}} = 0.15$\,GeV/$c$. A Gaussian fit to the left-hand-side and its extrapolation to positive $\delta\pt$ are shown for measured Pb--Pb events and for randomized Pb--Pb events ($\mu^{\rm LHS}$ and $\sigma^{\rm LHS}$ in GeV/$c$). The solid line is a fit to the $\delta\pt$ distribution for the randomized events with a $\Gamma$ distribution shifted to zero (Eq. 2) as approximation for the shape in case of independent particle emission.
$$\begin{align*} (2)   f^{\Gamma}(\delta\pt) = A \cdot a_{b} /\Gamma(a_{p}) \cdot (a_b \delta\pt+a_p)^{a_p-1} \cdot e^{-(a_b \delta\pt + a_p)} \end{align*}$$