In this paper, we presented our recently developed Dynamical Radiative and Elastic ENergy loss Approach (DREENA-C) framework, which is a fully optimized computational suppression procedure based on our state-of-the-art dynamical energy loss formalism in constant temperature finite size QCD medium. With this framework, we have generated, for the first time, joint R _AA and v ₂ predictions within our dynamical energy loss formalism. The predictions are generated for both light and heavy flavor probes, and different centrality regions in Pb + Pb collisions at the LHC, and compared with the available experimental data. While R _AA predictions agree with experimental data, v ₂ predictions qualitatively agree with, but are quantitatively visibly above, the experimental data (in disagreement with other models, which underestimate v ₂). Consistently with numerical predictions, through simple analytic analysis, we show that R _AA is insensitive to medium evolution (though highly sensitive to energy loss mechanisms), while v ₂ is highly sensitive to the evolution. As a major consequence for precision quark-gluon plasma (QGP) tomography, this then leaves a possibility to calibrate energy loss models on R _AA data, while using v ₂ to constrain QGP parameters that are in agreement with both high and low p _⊥ data.

We implement fully the algebraic Bethe ansatz for the XXX Heisenberg spin chain in the case when both boundary matrices can be brought to the upper-triangular form. We define the Bethe vectors which yield the strikingly simple expression for the off shell action of the transfer matrix, deriving the spectrum and the relevant Bethe equations. We explore further these results by obtaining the off shell action of the generating function of the Gaudin Hamiltonians on the corresponding Bethe vectors through the so-called quasi-classical limit. Moreover, this action is as simple as it could possibly be, yielding the spectrum and the Bethe equations of the Gaudin model

We study whether it is possible to use high-$p_{\perp }$ data/theory to constrain the temperature dependence of the shear viscosity over entropy density ratio $\eta /s$ of the matter formed in ultrarelativistic heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC). We use two approaches: (i) We calculate high-$p_{\perp }{R}_{AA}$ and flow coefficients $v_2, v_3$, and $v_4$ assuming different $(\eta /s)\left(T\right)$ of the fluid-dynamically evolving medium. (ii) We calculate the quenching strength ($\widehat{q}/T^3$) from our dynamical energy loss model and convert it to $\eta /s$ as a function of temperature. It turned out that the first approach cannot distinguish between different $(\eta /s)\left(T\right)$ assumptions when the evolution is constrained to reproduce the low-$p_{\perp }$ data. In distinction, $(\eta /s)\left(T\right)$ calculated using the second approach agrees surprisingly well with the $(\eta /s)\left(T\right)$ inferred through state-of-the-art Bayesian analyses of the low-$p_{\perp }$ data even in the vicinity of $T_c$, while providing much smaller uncertainties at high temperatures.

We propose a scheme for investigating the nonequilibrium aspects of small-polaron physics using an array of superconducting qubits and microwave resonators. This system, which can be realized with transmon or gatemon qubits, serves as an analog simulator for a lattice model describing a nonlocal coupling of a quantum particle (excitation) to dispersionless phonons. We study its dynamics following an excitation-phonon (qubit-resonator) interaction quench using a numerically exact approach based on a Chebyshev-moment expansion of the time-evolution operator of the system. We thereby glean heretofore unavailable insights into the process of the small-polaron formation resulting from strongly momentum-dependent excitation-phonon interactions, most prominently about its inherent dynamical timescale. To further characterize this complex process, we evaluate the excitation-phonon entanglement entropy and show that initially prepared bare-excitation Bloch states here dynamically evolve into small-polaron states that are close to being maximally entangled. Finally, by computing the dynamical variances of the phonon position and momentum quadratures, we demonstrate a pronounced non-Gaussian character of the latter states, with a strong antisqueezing in both quadratures.