On connection between the collider long-range near-side \u201cridge\u201d effect at |eta | < 2.4 and cosmic-ray coplanarity of most energetic particles

R A Mukhamedshin

doi:10.1140/epjc/s10052-022-10082-w

R A Mukhamedshin

Open Access

https://doi.org/10.1140/epjc/s10052-022-10082-w

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Abstract

Some coplanarity of most energetic subcores of gamma -ray–hadron families is observed in cosmic-ray experiments at E_0 gtrsim 10^{16} eV (sqrt{s} gtrsim 5 TeV). This effect requires appearance of some coplanar generation of most energetic particles in hadron-nucleus interactions. On the other hand, a long-range near-side “ridge” effect was observed in pp collisions at sqrt{s} = 7 TeV by the CMS Collaboration in two-particle varDelta eta - varDelta varphi correlation functions at |varDelta eta | gtrsim 3 and |varDelta varphi | approx 0. To improve a research for possible relationship of these phenomena, a phenomenological FANSY 2.0 model is designed to simulate hadron interactions using both traditional and coplanar modes for the hadron generation, QGSJ and CPG, respectively. The FANSY 2.0 reproduces LHC data on generation of unflavoured, strange and charmed hadrons. Model parameters of coplanar hadron generation are given. It is shown that the FANSY 2.0 CPG reproduces the near-side “ridge” effect at sqrt{s} = 7 TeV.

Highlights

One of phenomena obtained in mountain-based and stratospheric X-ray–emulsion chamber (XREC) experiments is a strong azimuthal effect that manifests itself in the form of a tendency to a coplanarity of most energetic subcores of so-called γ -ray–hadron families, i.e. groups of most energetic (E 10 TeV) particles in the central cores of relatively “young” extensive air showers (EAS)
This means that these showers do not reach their maximum development at the observation level, and numbers of most energetic particles (MEP) in these showers are higher than the average one
Five independent sets of experimental data [1,2,3,4,5,6,7,8,9,10,11,12] have been accumulated. It is high-mountain data obtained by the Pamir Collaboration with so-called “carbon” (C) and “lead” (Pb) XRECs on γ -ray families with measured energies Eγ ≥ 700 TeV [1,2,3,4,5] and Mt.Canbala Collaboration’s Fe-XRECs ( Eγ ≥ 500 TeV) [6]

Summary

Introduction

One of phenomena obtained in mountain-based and stratospheric X-ray–emulsion chamber (XREC) experiments is a strong azimuthal effect that manifests itself in the form of a tendency to a coplanarity of most energetic subcores of so-called γ -ray–hadron families, i.e. groups of most energetic (E 10 TeV) particles in the central cores of relatively “young” extensive air showers (EAS). This means that these showers do not reach their maximum development at the observation level, and numbers of most energetic particles (MEP) in these showers are higher than the average one.

On processing of experimental data

Coplanarity simulation

Discussion

Conclusion