On connection between the collider long-range near-side “ridge” effect at $$|\eta | < 2.4$$ and cosmic-ray coplanarity of most energetic particles
Р. А. Мухамедшин
Abstract
Abstract Some coplanarity of most energetic subcores of $$\gamma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>γ</mml:mi></mml:math> -ray–hadron families is observed in cosmic-ray experiments at $$E_0 \gtrsim 10^{16}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>E</mml:mi><mml:mn>0</mml:mn></mml:msub><mml:mo>≳</mml:mo><mml:msup><mml:mn>10</mml:mn><mml:mn>16</mml:mn></mml:msup></mml:mrow></mml:math> eV ( $$\sqrt{s} \gtrsim 5$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>≳</mml:mo><mml:mn>5</mml:mn></mml:mrow></mml:math> 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 $$\sqrt{s} = 7$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>7</mml:mn></mml:mrow></mml:math> TeV by the CMS Collaboration in two-particle $$\varDelta \eta - \varDelta \varphi $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>Δ</mml:mi><mml:mi>η</mml:mi><mml:mo>-</mml:mo><mml:mi>Δ</mml:mi><mml:mi>φ</mml:mi></mml:mrow></mml:math> correlation functions at $$|\varDelta \eta | \gtrsim 3$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>|</mml:mo><mml:mi>Δ</mml:mi><mml:mi>η</mml:mi><mml:mo>|</mml:mo><mml:mo>≳</mml:mo><mml:mn>3</mml:mn></mml:mrow></mml:math> and $$|\varDelta \varphi | \approx 0$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>|</mml:mo><mml:mi>Δ</mml:mi><mml:mi>φ</mml:mi><mml:mo>|</mml:mo><mml:mo>≈</mml:mo><mml:mn>0</mml:mn></mml:mrow></mml:math> . 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 $$\sqrt{s} = 7$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>7</mml:mn></mml:mrow></mml:math> TeV.