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This document summarizes the efforts of the EMMI Rapid Reaction Task Force on "Suppression and (re)generation of quarkonium in heavy-ion collisions at the LHC", centered around their 2019 and 2022 meetings. It provides a review of existing experimental results and theoretical approaches, including lattice QCD calculations and semiclassical and quantum approaches for the dynamical evolution of quarkonia in the quark-gluon plasma as probed in high-energy heavy-ion collisions. The key ingredients of the transport models are itemized to facilitate comparisons of calculated quantities such as reaction rates, binding energies, and nuclear modification factors. A diagnostic assessment of the various results is attempted and coupled with an outlook for the future. [ABSTRACT FROM AUTHOR]

A sample of the Ni-based superalloy AD730 was heat treated at a supersolvus temperature (1160 °C) then slowly cooled through the solvus temperature (1110 °C) at 10 °C/hr down to 1080 °C, i.e., a rate representative of the cooling conditions of an industrial-scale billet undergoing controlled cooling. The γ′ precipitate distribution which forms during this cooling was investigated, and a mix of continuous and discontinuous precipitation was found. The discontinuous γ′ precipitates were imaged using 3D tomography, and were shown to present very different sizes, morphologies, and aspect ratios when observed in different 2D imaging planes. The interaction between different populations of γ′ precipitate and recrystallization was investigated, and it was found that the discontinuous precipitates present more of a barrier to recrystallization than the continuous ones. This has been explained based on the different inter-precipitate spacings observed for the two populations. In addition to these γ′ precipitates which form during slow cooling, a fine and dense distribution of approximately spherical γ′ precipitates was found to form dynamically, during subsequent subsolvus forging, within unrecrystallized grains. [ABSTRACT FROM AUTHOR]

In this article, the scientific life of D. Gogny is recounted by several collaborators. His strong involvement in researches related to various fields of physics (such as nuclear, atomic and plasma physics as well as electromagnetism) appears clearly, as well as the progresses made in the understanding of fundamental physics. [ABSTRACT FROM AUTHOR]

Observations of distant supernovae indicate that the Universe is now in a phase of accelerated expansion the physical cause of which is a mystery. Formally, this requires the inclusion of a term acting as a negative pressure in the equations of cosmic expansion, accounting for about 75 per cent of the total energy density in the Universe. The simplest option for this ‘dark energy’ corresponds to a ‘cosmological constant’, perhaps related to the quantum vacuum energy. Physically viable alternatives invoke either the presence of a scalar field with an evolving equation of state, or extensions of general relativity involving higher-order curvature terms or extra dimensions. Although they produce similar expansion rates, different models predict measurable differences in the growth rate of large-scale structure with cosmic time. A fingerprint of this growth is provided by coherent galaxy motions, which introduce a radial anisotropy in the clustering pattern reconstructed by galaxy redshift surveys. Here we report a measurement of this effect at a redshift of 0.8. Using a new survey of more than 10,000 faint galaxies, we measure the anisotropy parameter β = 0.70 ± 0.26, which corresponds to a growth rate of structure at that time of f = 0.91 ± 0.36. This is consistent with the standard cosmological-constant model with low matter density and flat geometry, although the error bars are still too large to distinguish among alternative origins for the accelerated expansion. The correct origin could be determined with a further factor-of-ten increase in the sampled volume at similar redshift. [ABSTRACT FROM AUTHOR]

We present the first numerical application of a method that we have recently proposed to solve the Non Perturbative Renormalization Group equations and obtain the n-point functions for arbitrary external momenta. This method leads to flow equations for the n-point functions which are also differential equations with respect to a constant background field. This makes them, a priori, difficult to solve. However, we demonstrate in this paper that, within a simple approximation which turns out to be quite accurate, the solution of these flow equations is not more complicated than that of the flow equations obtained in the derivative expansion. Thus, with a numerical effort comparable to that involved in the derivative expansion, we can get the full momentum dependence of the n-point functions. The method is applied, in its leading order, to the calculation of the self-energy in a 3-dimensional scalar field theory, at criticality. Accurate results are obtained over the entire range of momenta. [ABSTRACT FROM AUTHOR]

This talk reviews the status of QCD calculations of photon and dilepton production rates in a quark-gluon plasma. Theses rates are known to order ${\cal O}(\alpha_{\mathrm {s}})$. Their calculations involve various resummations to account for well identified physical effects that are briefly described. Lattice calculations of the spectral functions give also access to the dilepton rates. Comparison with perturbative results points to inconsistencies in both approaches when the dilepton energy becomes small. [ABSTRACT FROM AUTHOR]

We compare our previously proposed hard-thermal-loop (HTL) resummed calculation of quark number susceptibilities using a self-consistent two-loop approximation to the quark density with a recent calculation of the same quantity at the one-loop level in a variant of HTL-screened perturbation theory. Besides pointing out conceptual problems with the latter approach, we show that it severely over-includes the leading-order interaction effects, while including none of the plasmon terms, which is the main reason for requiring improved resummation schemes. [ABSTRACT FROM AUTHOR]

We study the effects of repulsive interactions on the critical density for the Bose-Einstein transition in a homogeneous dilute gas of bosons. First, we point out that the simple mean field approximation produces no change in the critical density, or critical temperature, and discuss the inadequacies of various contradictory results in the literature. Then, both within the frameworks of Ursell operators and of Green's functions, we derive self-consistent equations that include correlations in the system and predict the change of the critical density. We argue that the dominant contribution to this change can be obtained within classical field theory and show that the lowest order correction introduced by interactions is linear in the scattering length, a, with a positive coefficient. Finally, we calculate this coefficient within various approximations, and compare with various recent numerical estimates. [ABSTRACT FROM AUTHOR]