Generalizedz-scaling in proton-proton collisions at high energies

Abstract

New generalization of z-scaling in inclusive particle production is proposed. The scaling variable z is fractal measure which depends on kinematical characteristics of the underlying sub-process expressed in terms of the momentum fractions x 1 and x 2 of the incoming protons. In the generalized approach, the x 1 and x 2 are functions of the momentum fractions y a and y b of the scattered and recoil constituents carried out by the inclusive particle and recoil object, respectively. The scaling function ψ(z) for charged and identified hadrons produced in proton-proton collisions is constructed. The fractal dimensions and heat capacity of the produced medium entering definition of the z are established to obtain energy, angular and multiplicity independence of the ψ(z). The scheme allows unique description of data on inclusive cross sections of charged particles, pions, kaons, antiprotons and lambdas at high energies. The obtained results are of interest to use z-scaling as a tool for searching for new physics phenomena of particle production in high transverse momentum and high multiplicity region at proton-proton colliders RHIC and LHC.

Top-QuarkpT-Spectra at LHC and Flavor Independence ofz-Scaling

“…Data on π − -meson spectra shown by the solid line serves as a reference data. The values of the fractal dimension δ = 0.5 and the parameter c = 0.25 are the same as used in our previous analyses [6,7,17]. We have set top = 0 in the case of the topquark, as no or negligible energy loss is assumed in the elementary tt production process.…”

“…It means that spectra of particles with the different flavour content can be described by an universal scaling function ψ(z) in z-presentation [6,7]. Our previous analysis was based on the observation that simultaneous energy, angular, and multiplicity independence of the z-scaling for negative pions, kaons, and anti-protons produced in proton-proton collisions gives the same shape of the scaling function.…”

“…Here we follow the basic ideas of the z-scaling concept [6,7]. At sufficiently high energies, a collision of hadrons or nuclei is considered as an ensemble of individual interactions of their constituents (partons, quarks, gluons).…”

“…The constant m N is the nucleon mass. The scaling function ψ(z) is expressed in terms of the experimentally measured inclusive cross section Ed 3 σ/dp 3 , multiplicity density dN/dη, and the total inelastic cross section σ in as follows [6] …”

“…The symmetry related to the ideas of self-similarity of hadron interactions at a constituent level is manifested by the z-scaling [4,5]. The scaling was used for analysis of inclusive spectra obtained at the accelerators U70, SppS, SPS, ISR, Tevatron and RHIC [6,7]. The scaling is treated as manifestation of self-similarity of the structure of the colliding objects (hadrons or nuclei), the interaction mechanism of their constituents, and the process of fragmentation into real hadrons.…”