For $\lambda \sim 2/E_R$ and $\delta _f < 0.1$ one gets the estimate for the free path length $$R_f>20/E_R \sim 4.5/\mu \sim 7\cdot 10^{-13} {\rm cm}.   \label{rfn}$$ This appears to be quite a reasonable estimate. The inequality sign shows that the partial width due to this particular effect is smaller than the total width.

Finally, the width of the ring can become larger due to the processes of resonance formation (hadronization of the gluon collective mode) and decays. However, this can be quantified only if the Monte Carlo program for jets with Cherenkov gluons is elaborated.

The energy loss can be calculated using the standard formula $$\frac {dE}{dx}=4\pi \alpha _S\int _{E_R-\Gamma _R}^{E_R}E\left (1-\frac {1}
{n^2(E)}\right )dE.       \label{dedx}$$ The integration limits define the most important region discussed above. With expression (\[ren\]) for $\rho $-meson one gets from (\[dedx\]) $$\frac {dE}{dx} \approx 1 \; {\rm GeV/fm}.     \label{dedn}$$ This estimate is an order of magnitude higher than the value of 0.1 GeV/fm obtained in the model of [@a] which is somewhat underestimated, in our opinion. It is determined by energies required to excite resonances. However, it is still smaller than the radiative loss.

Thus, using the RHIC data, we have estimated such parameters 