We analyze geometrical scaling (GS) of negative pion multiplicity $p_{\mathrm{T}}$ distributions at NA61/SHINE energies. We show that even though NA61/SHINE energies are low, one may expect to find GS in the particle spectra. We argue that qualitative behavior of ratios of multiplicities at different energies is in agreement with a simple picture of GS which is violated for $p_{\mathrm{T}}$ smaller than some nonperturbative scale $\Lambda$ and when larger Bjorken $x$ of one of the scattering patrons crosses $x_{\max }$ above which a gluonic cloud becomes dilute and quark degrees of freedom become important.

• Received 24 January 2013

DOI:https://doi.org/10.1103/PhysRevD.87.071502