Long-Range Rapidity Correlations in Heavy-Light Ion Collisions

Abstract

We study two-particle long-range rapidity correlations arising in the early stages of heavy ion collisions in the saturation/Color Glass Condensate framework, assuming for simplicity that one colliding nucleus is much larger than the other. We calculate the two-gluon production cross section while including all-order saturation effects in the heavy nucleus with the lowest-order rescattering in the lighter nucleus. We find four types of correlations in the two-gluon production cross section: (i) geometric correlations, (ii) HBT correlations accompanied by a back-to-back maximum, (iii) away-side correlations, and (iv) near-side azimuthal correlations which are long-range in rapidity. The geometric correlations (i) are due to the fact that nucleons are correlated by simply being confined within the same nucleus and may lead to long-range rapidity correlations for the produced particles without strong azimuthal angle dependence. Somewhat surprisingly, long-range rapidity correlations (iii) and (iv) have exactly the same amplitudes along with azimuthal and rapidity shapes: one centered around Δϕ=π with the other one centered around Δϕ=0 (here Δϕ is the azimuthal angle between the two produced gluons). We thus observe that the early-time CGC dynamics in nucleus-nucleus collisions generates azimuthal non-flow correlations which are qualitatively different from jet correlations by being long-range in rapidity. If strong enough, they have the potential of mimicking the elliptic (and higher-order even-harmonic) flow in the di-hadron correlators: one may need to take them into account in the experimental determination of the flow observables.

26 pages, 13 figurs; v2: some corrections and new figures included

References in corpus (19)

• The Color Glass Condensate
• Long-range angular correlations on the near and away side in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Observation of long-range near-side angular correlations in proton-lead collisions at the LHC
• Quark contribution to the small-$x$ evolution of color dipole
• Holography and colliding gravitational shock waves in asymptotically AdS_5 spacetime
• Dihadron azimuthal correlations in Au+Au collisions at sqrt(s_NN)=200 GeV
• Triumvirate of Running Couplings in Small-x Evolution
• The ridge in proton-proton collisions at the LHC
• Long Range Correlations and the Soft Ridge in Relativistic Nuclear Collisions
• Explanation of systematics of CMS p+Pb high multiplicity di-hadron data at ${\sqrt{s}}_{\mathrm{NN}}=5.02$ TeV
• Evidence for BFKL and saturation dynamics from di-hadron spectra at the LHC
• Angular Correlations in Gluon Production at High Energy
• Angular and long range rapidity correlations in particle production at high energy
• Running coupling and power corrections in nonlinear evolution at the high--energy limit
• High energy factorization in nucleus-nucleus collisions III. Long range rapidity correlations
• Long Range Forward-Backward Correlations and the Color Glass Condensate
• Modeling Heavy Ion Collisions in AdS/CFT
• Two-particle correlations in high energy collisions and the gluon four-point function
• On the long-range correlations in hadron-nucleus collisions

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