ar X iv : 1 70 4 . 08 13 8 v 1 [ he p - ph ] 2 6 A pr 2 01 7 Universal scaling of strange particle p T spectra in pp collisions

As a complementary study to that performed on the transverse momentum (pT) spectra of pions, kaons and protons in proton-proton (pp) collisions at LHC energies 0.9, 2.76 and 7 TeV, we present a scaling behaviour in the pT spectra of strange particles (K 0 S , Λ and Ξ) at these three energies. This scaling behaviour is exhibited when the spectra are expressed in a suitable scaling variable z = pT/K. The scaling parameter K is determined by the quality factor method. It increases with the center of mass energy ( √ s). The rates of the increase for K S , Λ and Ξ are various with one another, and they are larger than the rates for pions, kaons and protons. In the framework of the color string percolation model, K S, Λ and Ξ are produced through the decay of clusters with different size distributions, and the scaling behaviour is due to the invariance of the pT spectra produced by clusters under some transformation. We find that K is proportional to the fourth root of the string overlap degree, and the string overlap degree grows with √ s, which leads to the increase of K with √ s. What’s more, the growth of the string overlap degree with √ s for clusters producing strange particles is stronger than that for clusters producing pions, kaons and protons. PACS numbers: 13.85.Ni, 13.87.Fh Universal scaling of strange particle pT spectra in pp collisions 2