A nonflow subtraction framework for m-particle cumulants is developed and tested in HIJING simulations for O+O and d+Au collisions.
Observation of long-range elliptic anisotropies in $\sqrt{s}=$13 and 2.76 TeV $pp$ collisions with the ATLAS detector
8 Pith papers cite this work, alongside 317 external citations. Polarity classification is still indexing.
abstract
ATLAS has measured two-particle correlations as a function of relative azimuthal-angle, $\Delta \phi$, and pseudorapidity, $\Delta \eta$, in $\sqrt{s}$=13 and 2.76 TeV $pp$ collisions at the LHC using charged particles measured in the pseudorapidity interval $|\eta|$<2.5. The correlation functions evaluated in different intervals of measured charged-particle multiplicity show a multiplicity-dependent enhancement at $\Delta \phi \sim 0$ that extends over a wide range of $\Delta\eta$, which has been referred to as the "ridge". Per-trigger-particle yields, $Y(\Delta \phi)$, are measured over 2<$|\Delta\eta|$<5. For both collision energies, the $Y(\Delta \phi)$ distribution in all multiplicity intervals is found to be consistent with a linear combination of the per-trigger-particle yields measured in collisions with less than 20 reconstructed tracks, and a constant combinatoric contribution modulated by $\cos{(2\Delta \phi)}$. The fitted Fourier coefficient, $v_{2,2}$, exhibits factorization, suggesting that the ridge results from per-event $\cos{(2\phi)}$ modulation of the single-particle distribution with Fourier coefficients $v_2$. The $v_2$ values are presented as a function of multiplicity and transverse momentum. They are found to be approximately constant as a function of multiplicity and to have a $p_{\mathrm{T}}$ dependence similar to that measured in $p$+Pb and Pb+Pb collisions. The $v_2$ values in the 13 and 2.76 TeV data are consistent within uncertainties. These results suggest that the ridge in $pp$ collisions arises from the same or similar underlying physics as observed in $p$+Pb collisions, and that the dynamics responsible for the ridge has no strong $\sqrt{s}$ dependence.
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ATLAS presents first v_n (n=2-4) measurements in O+O and Ne+Ne collisions, showing a flow hierarchy and a central Ne+Ne v2 enhancement consistent with prolate neon deformation.
The first measurement of charged-particle dijet invariant mass spectra shows no significant nuclear modification in p-Pb collisions at low masses.
A conditional probability framework derives Maxwell-Boltzmann, Bose-Einstein and Fermi-Dirac statistics plus conservation-induced covariances from saddle-point marginals, then uses orthogonal projections to isolate conservation effects in PYTHIA-simulated p+Pb events.
ATLAS measures charged-particle pseudorapidity density and mean transverse momentum in O+O and Ne+Ne collisions at 5.36 TeV as a function of centrality and eta.
Formal solutions of Boltzmann moment equations demonstrate that relativistic hydrodynamics works far from equilibrium because non-perturbative modes and modified transport coefficients enable interpolation between free streaming and hydrodynamic regimes.
Toy models show multi-particle correlators can increase rather than reduce deviation from true flow harmonics in small collision systems.
CMS measures V_nΔ in pPb events at √s_NN = 8.16 TeV as a function of forward rapidity gap width, p_T, and multiplicity in γPb and IP Pb enriched samples, comparing to prior pp, pPb, and γp data plus event generators.
citing papers explorer
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Nonflow Subtraction Beyond Two-Particle Correlations
A nonflow subtraction framework for m-particle cumulants is developed and tested in HIJING simulations for O+O and d+Au collisions.
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Measurement of the azimuthal anisotropy of charged particles in $\sqrt{s_{\mathrm{NN}}}=5.36$ TeV $^{16}$O$+^{16}$O and $^{20}$Ne$+^{20}$Ne collisions with the ATLAS detector
ATLAS presents first v_n (n=2-4) measurements in O+O and Ne+Ne collisions, showing a flow hierarchy and a central Ne+Ne v2 enhancement consistent with prolate neon deformation.
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Dijet invariant mass of charged-particle jets in pp and p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV
The first measurement of charged-particle dijet invariant mass spectra shows no significant nuclear modification in p-Pb collisions at low masses.
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Equilibrium Statistics as Conditional Laws and Conservation-Induced Correlations
A conditional probability framework derives Maxwell-Boltzmann, Bose-Einstein and Fermi-Dirac statistics plus conservation-induced covariances from saddle-point marginals, then uses orthogonal projections to isolate conservation effects in PYTHIA-simulated p+Pb events.
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Measurements of charged-particle pseudorapidity and transverse momentum distributions in O+O and Ne+Ne collisions at $\sqrt{s_{_\text{NN}}} = 5.36$ TeV with the ATLAS detector
ATLAS measures charged-particle pseudorapidity density and mean transverse momentum in O+O and Ne+Ne collisions at 5.36 TeV as a function of centrality and eta.
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Validity of relativistic hydrodynamics beyond local equilibrium
Formal solutions of Boltzmann moment equations demonstrate that relativistic hydrodynamics works far from equilibrium because non-perturbative modes and modified transport coefficients enable interpolation between free streaming and hydrodynamic regimes.
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Effectiveness of nonflow suppression using multi-particle correlators
Toy models show multi-particle correlators can increase rather than reduce deviation from true flow harmonics in small collision systems.
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Dependence of two-particle azimuthal correlations on the forward rapidity gap width in pPb collisions at $\sqrt{s_\mathrm{NN}}$ = 8.16 TeV
CMS measures V_nΔ in pPb events at √s_NN = 8.16 TeV as a function of forward rapidity gap width, p_T, and multiplicity in γPb and IP Pb enriched samples, comparing to prior pp, pPb, and γp data plus event generators.