On connection between the collider long-range near-side “ridge” effect at $$|\eta | < 2.4$$ | η | < 2.4 and cosmic-ray coplanarity of most energetic particles

Abstract

Abstract Some coplanarity of most energetic subcores of $$\gamma $$ γ -ray–hadron families is observed in cosmic-ray experiments at $$E_0 \gtrsim 10^{16}$$ E 0 ≳ 10 16 eV ( $$\sqrt{s} \gtrsim 5$$ s ≳ 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 $$\sqrt{s} = 7$$ s = 7 TeV by the CMS Collaboration in two-particle $$\varDelta \eta - \varDelta \varphi $$ Δ η - Δ φ correlation functions at $$|\varDelta \eta | \gtrsim 3$$ | Δ η | ≳ 3 and $$|\varDelta \varphi | \approx 0$$ | Δ φ | ≈ 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 $$\sqrt{s} = 7$$ s = 7 TeV.