Saturation momentum scale extracted from semi-inclusive transverse spectra in high-energy pp collisions

Abstract

Geometric scaling is well confirmed for transverse momentum distributions observed in protonproton collisions at LHC energies. We introduced multiplicity dependence on a saturation momentum of the geometrical scaling, assuming the scaling holds for semi-inclusive distributions as well as for inclusive distributions. The saturation momentum is usually given by Bjorken's x variable, but redefinition of the scaling variable can make the saturation momentum a function of collision energy W . We treat the energy as a free parameter (denoted W * to distinguish it from W ) and associate the energy-dependent saturation momentum Qsat(W * ) with particle number density. By using Qsat(W * ) for a scaling variable τ , we show semi-inclusive distributions can be geometrically scaled. i.e., all semi-inclusive spectra observed at W =0.90, 2.76 and 7.00 TeV overlap one universal function. The particle density dependences of mean transverse momentum pT for LHC energies scales in terms of Qsat(W * ). Furthermore, our model explains a scaling property of event-by-event pT fluctuation measure √ Cm/ pT at LHC energies for pp collisions, where Cm is two-particle transverse momentum correlator. Our analysis of the pT fluctuation makes possible to evaluate a non-perturbative coefficient of the gluon correlation function.

Investigating the diffractive gluon jet production in lepton-ion collisions

“…For instance, in Ref. [28] the proton saturation scale Q 2 s,p is obtained from the multiplicities of charged hadrons in pp collisions by using local parton-hadron duality and geometric scaling property (similar investigations were done for pA [29] and AA collisions [30]). We present the probable region where the peaks occur, κ ≈ a × Q s,A (x IP ) (a is a constant of order of unity), and it was shown that the quantity κ 2 σ scaled presents universal behavior as a function of the scaling variable, τ = κ/Q s .…”

Investigating the inclusive transverse spectra in high-energy pp collisions in the context of geometric scaling framework

“…The description of geometric scaling in the semi-inclusive transverse momentum spectra in pp collisions, taking into account the same formalism, has been done in Ref. [61]. In [61], the inclusive distribution with fixed multiplicity or limited multiplicity class is considered, and it is assumed to obey the same relations (18) and (20) as for inclusive case.…”

“…[61]. In [61], the inclusive distribution with fixed multiplicity or limited multiplicity class is considered, and it is assumed to obey the same relations (18) and (20) as for inclusive case. In addition, the replacements…”

Chiral phase transition within the linear sigma model in the Tsallis nonextensive statistics based on density operator

“…Power-like distributions have been used to describe momentum distributions in high energy collisions. Many researchers have studied momentum distributions, and have used Tsallis-type distributions [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. It has been reported that Tsallis-type distributions describe well momentum distributions.…”

“…The deviation from the Boltzmann-Gibbs statistics is small at high energies, and the values of |1−q| are close to 0.1. The effects of the small deviation from a e-mail: m isihar@koriyama-kgc.ac.jp the Boltzmann-Gibbs statistics on physical quantities, such as correlation and fluctuation [22,[26][27][28][29], have been studied.…”