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I discuss several ideas that may help to disentangle between initial state effects present, e.g., in the color glass condensate, and final state effects driven, e.g., by hydrodynamics or transport models.

We show that the incoherent elastic scattering of partons, as present in a multi-phase transport model (AMPT), with a modest parton-parton cross-section of σ = 1.5 – 3 mb , naturally explains the long-range two-particle azimuthal correlations as observed in p+Pb collisions at the LHC. The elliptic, v2, and triangular, v3, Fourier coefficients are in good agreement with the CMS data. An escape mechanism was proposed recently to explain the AMPT results. We demonstrate that parton scatterings are directly responsible for generating the azimuthal anisotropy.

The preliminary STAR data for proton cumulants for central collisions at \sqrt{s}=7.7 GeV are consistent with a two-component proton multiplicity distribution. We show that this two-component distribution is statistics friendly in that factorial cumulants of surprisingly high orders may be extracted with a relatively small number of events. As a consequence the two-component model can be tested and verified right now with the presently available STAR data from the first phase of the RHIC beam energy scan., Proceedings, Quark Matter 2019, Wuhan

© 2017 The Author(s) We discuss the relation between particle number cumulants and genuine correlation functions. It is argued that measuring multi-particle correlation functions could provide cleaner information on possible non-trivial dynamics in heavy-ion collisions.

We compute analytically the multi-particle eccentricities, \epsilon_m {2n}, for systems dominated by fluctuations, such as proton-nucleus collisions at the Large Hadron Collider. In particular, we derive a general relation for . We further discuss the relations between various multi-particle eccentricities and demonstrate that \epsilon_2{2} > \epsilon_2{4} \simeq \epsilon_2{6} \simeq \epsilon_2{8}, in agreement with recent numerical calculations in a Glauber model., Comment: 6 pages, 1 figure

The rapidity dependence of elliptic, $v_2$, and triangular, $v_3$, flow coefficients in proton-nucleus (p+A) collisions is predicted in hydrodynamics and in a multi-phase transport model (AMPT). We find that $v_n$ ($n=2,3$) on a nucleus side is significantly larger than on a proton side and the ratio between the two, $v_n^{\rm Pb}/v_n^{\rm p}$, weekly depends on the transverse momentum of produced particles., 6 pages, 8 figures

We show that the incoherent elastic scattering of partons, as present in a multi-phase transport model (AMPT), with a modest parton-parton cross-section of $\sigma=1.5 - 3$ mb, naturally explains the long-range two-particle azimuthal correlation as observed in proton-proton and proton-nucleus collisions at the Large Hadron Collider., Comment: 7 pages, 6 figures; 2 new figures added, final published version

We discuss various contributions to the event-by-event charge asymmetry dependence of π + and π − elliptic flow, recently measured by the STAR Collaboration at RHIC. It is shown that under general assumptions, the difference between v 2 + and v 2 − at a given fluctuating value of an asymmetry parameter, A , is a linear function of A , as observed in the preliminary data. We discuss two mechanisms that are qualitatively consistent with the experimental data and result in a signal of the correct order of magnitude. Our subsequent hydrodynamic calculations, assuming local charge conservation at freeze-out, yield a qualitative and partial quantitative understanding of the observed signal, so offering a detailed test of the hydrodynamic model in heavy-ion collisions.

We use as a starting point the original, central inclusive Bialas-Landshoff model for Higgs and dijet production by a double pomeron exchange in pp collisions. Next we propose the simple extension of this model to the exclusive processes. We find the extended model to be consistent with the CDF Run I, II upper limits for double diffractive exclusive dijet production. The predictions for the exclusive Higgs boson production cross sections at the Tevatron and the LHC energies are also presented., 11 pages, 3 figures, to be published in Phys. Lett. B