The continuum limit of quark number susceptibilities

We report the continuum limit of quark number susceptibilities in quenched QCD. Deviations from ideal gas behaviour at temperature T increase as the lattice spacing is decreased from T/4 to T/6, but a further decrease seems to have very little effect. The measured susceptibilities are 20% lower than the ideal gas values, and also 10% below the hard thermal loop (HTL) results. The off-diagonal susceptibility is several orders of magnitude smaller than the HTL results. We verify a strong correlation between the lowest screening mass and the susceptibility. We also show that the quark number susceptibilities give a reasonable account of the Wroblewski parameter, which measures the strangeness yield in a heavy-ion collision.Comment: 8 pages, 5 figure

Heavy-ion physics: freedom to do hot, dense, exciting QCD

In these two lectures I review the basics of heavy-ion collisions at relativistic energies and the physics we can do with them. I aim to cover the basics on the kinematics and observables in heavy-ion collider experiments, the basics on the phenomenology of the nuclear matter phase diagram, some of the model building and simulations currently used in the heavy-ion physics community and a selected list of amazing phenomenological discoveries and predictions.Comment: These lectures were given at the 2019 CERN Latin-American School of High-Energy Physics in Cordoba, Argentina, 13 - 26 March 2019 and the notes have been submitted to proceedings of CLASHEP 2019. These lecture notes are based on previous Heavy-Ion and extreme QCD lectures given at CLASHEP by A. Ayala (2017), E. Fraga (2015) and J. Takahashi (2013

Microscopic theory of the Casimir force at thermal equilibrium: large-separation asymptotics

We present an entirely microscopic calculation of the Casimir force $f(d)$ between two metallic plates in the limit of large separation $d$. The models of metals consist of mobile quantum charges in thermal equilibrium with the photon field at positive temperature $T$. Fluctuations of all degrees of freedom, matter and field, are treated according to the principles of quantum electrodynamics and statistical physics without recourse to approximations or intermediate assumptions. Our main result is the correctness of the asymptotic universal formula f(d) \sim -\frac{\zeta(3) \kB T}{8\pi d^3}, $d\to\infty$. This supports the fact that, in the framework of Lifshitz' theory of electromagnetic fluctuations, transverse electric modes do not contribute in this regime. Moreover the microscopic origin of universality is seen to rely on perfect screening sum rules that hold in great generality for conducting media.Comment: 34 pages, 0 figures. New version includes restructured intro and minor typos correcte

The gauge-string duality and heavy ion collisions

I review at a non-technical level the use of the gauge-string duality to study aspects of heavy ion collisions, with special emphasis on the trailing string calculation of heavy quark energy loss. I include some brief speculations on how variants of the trailing string construction could provide a toy model of black hole formation and evaporation. This essay is an invited contribution to "Forty Years of String Theory" and is aimed at philosophers and historians of science as well as physicists.Comment: 21 page

Dynamics of Nonequilibrium Deposition with Diffusional Relaxation

Models of adhesion of extended particles on linear and planar substrates are of interest in interpreting surface deposition in colloid, polymer, and certain biological systems. An introduction is presented to recent theoretical advances in modeling these processes. Effects of diffusional relaxation are surveyed in detail, including results obtained by analytical, large-scale numerical, mean-field and scaling approaches.Comment: Review article to appear in Annual Reviews in Computational Physics; 24 pages in plain TeX + 4 PostScript figure

Intraflagellar transport delivers tubulin isotypes to sensory cilium middle and distal segments.

Sensory cilia are assembled and maintained by kinesin-2-dependent intraflagellar transport (IFT). We investigated whether two Caenorhabditis elegans α- and β-tubulin isotypes, identified through mutants that lack their cilium distal segments, are delivered to their assembly sites by IFT. Mutations in conserved residues in both tubulins destabilize distal singlet microtubules. One isotype, TBB-4, assembles into microtubules at the tips of the axoneme core and distal segments, where the microtubule tip tracker EB1 is found, and localizes all along the cilium, whereas the other, TBA-5, concentrates in distal singlets. IFT assays, fluorescence recovery after photobleaching analysis and modelling indicate that the continual transport of sub-stoichiometric numbers of these tubulin subunits by the IFT machinery can maintain sensory cilia at their steady-state length

The Possibility of Increasing the Achromatic Tone Values of FOGRA 51 Standards Achieved by the Modification of in Line Pre-Treatment of the Printing Substrate

For high-quality black & white printing realized with an electrophotography printing machine, it is necessary to prepare the printing substrate. For optimal adhesion of the black liquid electrophotography ink to the printing substrate, it is necessary to apply additional treatment to meet ideal substrate surface tension by means of corona treatment and/or coating with fluid for regulating the surface tension (primer). This paper examines the influence of the corona power and the thickness of used fluid for the regulation of surface tension on the achromatic digital reproduction quality. Within the electrophotography printing process, this implies determining the differences in the colour gamut volume, the structure of characteristic screening elements, the amplitude-modulated screening, and the increase in the number of colour separations. The results show that the optimal colour tone values, colour gamut, and dot gain, high quality of digital prints will be realized without the use of the fluid for the regulation of surface tension and without activation of the corona power. That confirms that the FOGRA values for industrial standards can be used for quality electrophotography printing