on the scattering energy $W$, whereas Tsallis exponent $n$ is in the first approximation energy independent. Finally, we shall conclude in Sect. \[concl\].

Scaling properties of $p_{\mathrm{T}}$ distributions of identified particles {#scaling}
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Throughout this paper we shall use recent ALICE data for the $p_{\mathrm{T}}$ spectra at 0.9, 2.76 and 7 TeV [@ALICE]. In the latter case the data cover wide $p_{\mathrm{T}}$ range from 0.1 to 19 GeV/$c$ (for pions). Unfortunately available pion data for 0.9 TeV span over much narrower range: 0.1 - 2.5 GeV/$c$, and for 2.76 TeV from 2.1 to 19 GeV/$c$, and similarly for kaons and protons where, however, there is no overlap between 0.9 TeV and 2.76 TeV points. For this reason the analysis presented in this paper can be only qualitative.

![Illustration of geometrical scaling in scaling variable $\tau_{p_{\rm T}}$. Multiplicity ratios $R_{W_{1}/W_{2}}$ for $W_{1}=7$ TeV are plotted as functions of scaling variable $\tau_{p_{\rm T}}$ for pions (red triangles: “up” for $W_{2} =2.76$ TeV, “down” for $W_{2}=0.9$ TeV) kaons (blue triangles: “right” for $W_{2}
=2.76$ TeV, “left” for $W_{2}=0.9$ TeV) and protons (back circles for $W_{2}
=2.76$ TeV and black squares $W_{2}=0.9$ TeV) for different values of the exponent $\lambda$ a) $\lambda=0$, b) $\lambda=0.2$, 