| 1. |
- Fernandez, J. L. Abelleira, et al.
(author)
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A Large Hadron Electron Collider at CERN
- 2012
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In: Journal of Physics G. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 39:7
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Journal article (peer-reviewed)
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| 2. |
- Boguslavski, K., et al.
(author)
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Heavy quark diffusion coefficient during hydrodynamization - non-equilibrium vs. equilibrium
- 2024
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In: Proceedings of Science. - 1824-8039. ; 438
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Conference paper (peer-reviewed)abstract
- We compute the heavy quark momentum diffusion coefficient using effective kinetic theory for a system going through bottom-up isotropization until approximate hydrodynamization. We find that when comparing the nonthermal diffusion coefficient to the thermal one for the same energy density, the observed deviations throughout the whole evolution are within 30% from the thermal value. For thermal systems matched to other quantities we observe considerably larger deviations. We also observe that the diffusion coefficient in the transverse direction dominates at large occupation number, whereas for an underoccupied system the longitudinal diffusion coefficient dominates. Similarly, we study the jet quenching parameter, where we obtain a smooth evolution connecting the large values of the glasma phase with the smaller values in the hydrodynamical regime.
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| 3. |
- Boguslavski, K., et al.
(author)
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Heavy quark diffusion coefficient in heavy-ion collisions via kinetic theory
- 2024
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In: Physical Review D. - 2470-0010. ; 109:1
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Journal article (peer-reviewed)abstract
- We compute the heavy quark momentum diffusion coefficient κ using QCD kinetic theory for a system going through bottom-up isotropization in the initial stages of a heavy ion collision. We find that the values of κ are within 30% from a thermal system at the same energy density. When matching for other quantities we observe considerably larger deviations. We also observe that the diffusion coefficient in the transverse direction is larger at high occupation numbers, whereas for an underoccupied system the longitudinal diffusion coefficient dominates. The behavior of the diffusion coefficient can be understood on a qualitative level based on the Debye mass mD and the effective temperature of soft modes T∗. Our findings for the kinetic evolution of κ in different directions can be used in phenomenological descriptions of heavy quark diffusion and quarkonium dynamics to include the impact of preequilibrium stages.
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| 4. |
- Boguslavski, K., et al.
(author)
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Jet momentum broadening during initial stages in heavy-ion collisions
- 2024
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In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 850
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Journal article (peer-reviewed)abstract
- We study the jet quenching parameter qˆ in the initial pre-equilibrium stages of heavy-ion collisions using the QCD kinetic theory description of the anisotropic quark-gluon plasma. This allows us to smoothly close the gap in the literature between the early glasma stage of the collision and the onset of hydrodynamics. We find that the pre-hydrodynamic evolution of qˆ during the bottom-up kinetic scenario shows little sensitivity to the initial conditions, jet energies and models of the transverse momentum cutoff. We also observe that, similarly to the glasma case, the jet quenching parameter is enhanced along the beam axis as compared to the transverse direction during most of the kinetic evolution.
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| 5. |
- Boguslavski, K., et al.
(author)
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Limiting attractors in heavy-ion collisions
- 2024
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In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 852
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Journal article (peer-reviewed)abstract
- We study universal features of the hydrodynamization process in heavy-ion collisions using QCD kinetic theory simulations for a wide range of couplings. We introduce the new concept of limiting attractors, which are obtained by extrapolation to vanishing and strong couplings. While the hydrodynamic limiting attractor emerges at strong couplings and is governed by the viscosity-related relaxation time scale τR, we identify a bottom-up limiting attractor at weak couplings. It corresponds to the late stages of the perturbative bottom-up thermalization scenario and exhibits isotropization on the time scale τBMSS=αs−13/5/Qs. In contrast to hydrodynamic limiting attractors, at finite couplings the bottom-up limiting attractor provides a good universal description of the pre-hydrodynamic evolution of jet and heavy-quark momentum broadening ratios qˆyy/qˆzz and κT/κz. We also provide parametrizations for these ratios for phenomenological studies of pre-equilibrium effects on jets and heavy quarks.
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| 6. |
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| 7. |
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| 8. |
- Nivette, Amy E., et al.
(author)
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A global analysis of the impact of COVID-19 stay-at-home restrictions on crime
- 2021
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In: Nature Human Behaviour. - : Nature Publishing Group. - 2397-3374. ; 5, s. 868-877
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Journal article (peer-reviewed)abstract
- The implementation of COVID-19 stay-at-home policies was associated with a considerable drop in urban crime in 27 cities across 23 countries. More stringent restrictions over movement in public space were predictive of larger declines in crime. The stay-at-home restrictions to control the spread of COVID-19 led to unparalleled sudden change in daily life, but it is unclear how they affected urban crime globally. We collected data on daily counts of crime in 27 cities across 23 countries in the Americas, Europe, the Middle East and Asia. We conducted interrupted time series analyses to assess the impact of stay-at-home restrictions on different types of crime in each city. Our findings show that the stay-at-home policies were associated with a considerable drop in urban crime, but with substantial variation across cities and types of crime. Meta-regression results showed that more stringent restrictions over movement in public space were predictive of larger declines in crime.
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| 9. |
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