Multiplicity dependencies of midrapidity transverse momentum spectra of identified charged particles in $p+p$ collisions at $(s)^{1/2}$ = 13 TeV at LHC

Multiplicity dependencies of midrapidity $p_t$ spectra of identified charged particles in inelastic $p+p$ collisions at $(s)^{1/2} = $13 TeV at the Large Hadron Collider (LHC), measured by ALICE Collaboration, have been analyzed. The combined minimum $χ^2$ fits with thermodynamically consistent Tsallis function as well as Hagedorn function with the embedded transverse flow describe quite satisfactorily the $p_t$ spectra of particles in the studied 10 different classes of charged-particle multiplicity in inelastic $p+p$ collisions at $(s)^{1/2} = $13 TeV. The obtained effective temperatures $T$ of thermodynamically consistent Tsallis function demonstrate a consistent growth with an increase in multiplicity of charged particles in inelastic $p+p$ collisions at $(s)^{1/2} = $13 TeV, and the corresponding $T$ versus the average charged-particle (pseudorapidity) multiplicity density $(〈dN_{ch}/dη〉)$ dependence is described very well by the simple power function with exponent parameter ≈ (1/3) in the whole analyzed range $〈dN_{ch}/dη〉 > 4$. It is found that the transverse (radial) flow becomes significant at higher multiplicity events in $p+p$ collisions at $(s)^{1/2} = $13 TeV, reaching the maximum value $〈β_t〉 = 0.28 ± 0.02$ at the largest studied multiplicity density $〈dN_{ch}/dη〉 = 26.02 ± 0.35$. It is estimated from analysis of $T_0$ and $〈β_t〉$ versus $〈dN_{ch}/dη〉$ dependencies, obtained using Hagedorn function with the embedded transverse flow, that the probable onset of deconfinement phase transition in inelastic $p+p$ collisions at $(s)^{1/2} = 13$ TeV occurs at $〈dN_{ch}/dη〉$ $\approx 7.1 \pm 0.2$.