Intermittency and erraticity of charged particles produced in ²⁸Si-Ag/Br interaction at 14.5 A GeV

Abstract

In this paper, we present the intermittency and the erraticity analyses of the distributions of charged particles produced in 28 Si-Ag/Br interaction at incident energy 14.5 A GeV. The experimental results are compared with a Monte Carlo simulation using ultra-relativistic quantum molecular dynamics (UrQMD) model. The experimental data show the presence of a nonstatistical component in the produced charged-particle density. Neither the UrQMD simulation nor the purely statistical simulation was found to match the experimental data. The present set of results are compared to those obtained in similar measurements from earlier high-energy nucleus-nucleus experiments. PACS Nos: 25.75.-q, 25.70.Mn, 24.60.KyRésumé : Nous soulignons ici le caractère intermittent et erratique dans l'analyse de la distribution des particules chargées dans les interactions 28 Si-Ag/Br à l'énergie incidente de 14,5 A GeV. Nous comparons les résultats expérimentaux avec une simulation Monte Carlo utilisant le modèle ultra-relativiste de dynamique moléculaire quantique (UrQMD). Les données expérimentales indiquent la présence d'une composante non statistique dans la densité de particules chargées produites. Ni la simulation UrQMD ni la simulation purement statistique n'arrivent à reproduire les données expérimentales. Nous comparons nos résultats avec ceux obtenus dans des mesures similaires lors d'expériences antérieures de collisions noyau-noyau à haute énergie.[Traduit par la Rédaction]

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“…As the simulated data do not exhibit any anisotropy in the (η, ϕ) plane, subsequently we did not extend our self-affine analysis to the (UrQMD+BEC) case. We should mention that all experimental β q values are also several times larger than the intermittency indices (φ q ) obtained in the (1d) analysis of the same set of data [17]. It has been argued [29] that the phase-space density of multiparticle production is anisotropic, and the upward bending in the SFM plot is a direct consequence of this anisotropy.…”

“…Very recently, we have performed a (1d) analysis of a set of 28 Si-Ag/Br data at an incident energy of 14.5A GeV [17], where the experimental measurements are compared with a set of simulated data based on the UrQMD code [18]. We observed that the experimental intermittency strength in the azimuthal (ϕ) space is approximately twice as large as that in the η-space, while the UrQMD model produces negligible intermittency in both spaces.…”

Multifractal detrended fluctuation analysis of particle density fluctuations in high-energy nuclear collisions

“…In one such analysis [30] the MF-DFA method is adopted to construct the multifractal spectrum of shower track distribution in Au + Au collision at 200A GeV, but without comparing the experiment with any simulation. (solid circles) [32,34], the G q moment (open circles) and the T q moment (solid triangles) analysis [35,36]. Left panel: 28 Si + Ag/Br interaction at 14.5A GeV and right panel: 32 S + Ag/Br interaction at 200A GeV.…”

“…(15). Corresponding D q values obtained from Hwa's technique of G q moments, Takagi's technique of T q moment [35] and the SFM [32] are also plotted together. Separate diagrams are drawn for the UrQMD data to avoid mutual overlapping of the points.…”

“…In our previous analyses of these data in terms of the SFM [32][33][34] and the multifractal (G q and T q ) moments [35,36], it was found that the single particle η distributions are multifractal in nature. In our previous analyses the 28 Si + Ag/Br data [32,33,35] were compared with the UrQMD model [37,38] while the 32 S + Ag/Br data [34,36] were compared with the Lund FRITIOF model [39].…”