Related papers: Hard (State) Problems
Stellar-mass black holes in the low-hard state may hold clues to jet formation and basic accretion disk physics, but the nature of the accretion flow remains uncertain. A standard thin disk can extend close to the innermost stable circular…
Hard QCD processes in ultrarelativistic heavy-ion collisions become increasingly relevant and they can be used as probes of the dense matter formed during the violent scatterings. We will discuss how one can use these hard probes to study…
Analytical radially self-similar models are the best available solutions describing disk-winds but need several improvements. In a previous article, we introduced models of jets from truncated disks, i.e. evolved in time numerical…
The nature and geometry of the hard state in black hole binaries is controversial. The broadband continuum spectrum and fast variability properties can be explained in a model where the inner disc evaporates into a geometrically thick, hot…
In the past years significant progress has been made toward achieving a quantitative understanding of jets and their substructure in high-energy proton-proton collisions from first principles in QCD. Precise measurements have become…
We have accumulated multiwavelength lightcurves for eight black hole X-ray binaries which have been observed to enter a supposed ``soft X-ray transient'' outburst, but which in fact remained in the low/hard state throughout the outburst.…
Jet tomography has become a powerful tool for the study of properties of dense matter in high-energy heavy-ion collisions. I will discuss recent progresses in the phenomenological study of jet quenching, including momentum, colliding energy…
Quantum Chromodynamics (QCD) is a firmly established part of the Standard Model, yet its long distance properties remain challenging at a conceptual level. In recent years significant experimental and theoretical progress has been made…
The suppression and modification of high-energy objects, like jets, in heavy-ion collisions provide an important window to access the degrees of freedom of the quark-gluon plasma on different length scales. Despite increasingly precise and…
Hard scattered partons are predicted to be well calibrated probes of the hot and dense medium produced in heavy ion collisions. Interactions of these partons with the medium w ill result in modifications of internal jet structure in Au+Au…
The discovery and subsequent study of microquasars lead to major progress in our understanding of: 1) the nature of relativistic jets seen elsewhere in the universe, and 2) the connection between the accretion onto compact objects and the…
We present a unified semi-quantitative model for the disc-jet coupling in black hole X-ray binary systems. We argue that during the rising phase of a black hole transient outburst the steady jet known to be associated with the canonical…
Observational constraints on the configuration of the black hole (BH)-accretion disk-jet system are crucial to understanding BH spin, accretion disk physics, and jet formation. The recently reported variation in the M87 jet position angle…
Recent observations of two black hole candidates (GX 339-4 and J1753.5-0127) in the low-hard state (L_X/L_Edd ~ 0.003-0.05) suggest the presence of a cool accretion disk very close to the innermost stable orbit of the black hole. This runs…
While the hard phase of the strong interaction is well described by perturbative QCD, the soft hadronization phase is less understood. Benefiting from the high statistics from e+e- experiments at the Z0 resonance, it is possible to impose…
Hard probes in the context of ultrarelativistic heavy ion collisions represent a key class of observables studied to gain informations about the QCD medium created in such collisions. However, in practice the so-called jet tomography has…
The morphologies of detected jets in X-ray binaries are almost as diverse as their number. This is due to different jet properties and ambient media that these jets encounter. It is important to understand the physics of these objects and…
The 2023/24 NICER monitoring campaign of the 7 Crab bright black hole X-ray binary Swift J1727.8-1613 covered the outburst in almost all accretion states. High-quality data are available in the high-Eddington-fraction hard-intermediate…
The main experimental results on jet production at HERA are reviewed. A study of jet shapes shows that the internal structure of jets is well understood. The potential to accurately determine the strong coupling constant using jet rates is…
X-ray signatures of outflowing gas have been detected in several accreting black-hole binaries, always in the soft state. A key question raised by these observations is whether these winds might also exist in the hard state. Here, we carry…