Anisotropic flow in the few collisions regime: application to bottomonia

Considering the kinetic Boltzmann equation in the limit of very few collisions, we study the evolution of the phase space distribution of bottomonia interacting with an expanding gas of massless partons. We investigate the scaling of the anisotropic flow coefficients on the initial eccentricities and the inverse Knudsen number, and compute their transverse momentum dependence.Comment: 4 pages, 1 figure, Presented by N.K. at Hot Quarks 2018 - Workshop for young scientists on the physics of ultrarelativistic nucleus-nucleus collisions, Texel, The Netherlands, September 7-14 2018, Submitted to MDPI Proceedings. v2: Figure corrected + minor change

Scaling behavior of anisotropic flow harmonics in the far from equilibrium regime

Borghini N, Feld S, Kersting N. Scaling behavior of anisotropic flow harmonics in the far from equilibrium regime. European Physical Journal C. 2018;78(10): 832.We consider the development of anisotropic flow in an expanding system of particles undergoing very few rescatterings, using a kinetic-theoretical description with a nonlinear collision term. We derive the scaling behaviors of the harmonic coefficients $v_n$ on the initial-state eccentricities and the mean number of rescatterings, and argue that hexagonal flow $v_6$ should follow a nontrivial behavior, different from that of the lower harmonics. Our findings should be observable in experimental data for small systems

Endophilia or Exophobia:Beyond Discrimination

The discrimination literature treats outcomes as relative. But does a differential arise because agents discriminate against others - exophobia - or because they favour their own kind - endophilia? Using a field experiment that assigned graders randomly to students' examinations that did/did not contain names, we find favouritism but no discrimination by nationality nor by gender. We are able to identify these preferences under a wide range of behavioural scenarios regarding the graders. That endophilia dominates exophobia alters how we should measure discriminatory wage differentials and should inform the formulation of anti-discrimination policy

Kinetic freeze out from an anisotropic fluid in high-energy heavy-ion collisions: particle spectra, Hanbury Brown-Twiss radii, and anisotropic flow

Dissipative relativistic fluid-dynamical descriptions of the extended fireball formed in high-energy heavy-ion collisions are quite successful, yet require a prescription for converting the fluid into particles. We present arguments in favour of using a locally anisotropic momentum distribution for the particles emitted from the fluid, so as to smooth out discontinuities introduced by the usual conversion prescriptions. Building on this ansatz, we investigate the effect of the asymmetry on several observables of heavy ion physics.Comment: 7 pages, 6 figures; v2: accepted for publication in Eur. Phys. J.

Statistical analysis of initial state and final state response in heavy-ion collisions

We develop a general decomposition of an ensemble of initial density profiles in terms of an average state and a basis of modes that represent the event-by-event fluctuations of the initial state. The basis is determined such that the probability distributions of the amplitudes of different modes are uncorrelated. Based on this decomposition, we quantify the different types and probabilities of event-by-event fluctuations in Glauber and Saturation models and investigate how the various modes affect different characteristics of the initial state. We perform simulations of the dynamical evolution with KoMPoST and MUSIC to investigate the impact of the modes on final-state observables and their correlations.Comment: 58 pages, 40 figure

Une démarche préliminaire vers une caractérisation fiable en dynamique. "Application à un composite thermoplastique"

De nombreuses études sur les matériaux composites à matrice organique, en particulier thermoplastique, ont montré que le comportement mécanique de tels matériaux est sensible à la vitesse de sollicitation. Cependant, il n’existe pas de consensus permettant de définir les moyens de caractériser, comparer et modéliser ce genre de comportement. Cette étude se focalise sur une démarche expérimentale visant à caractériser de manière robuste le comportement mécanique d’un composite à matrice polyamide 6,6 renforcé de fibres de verre tissées. Une large gamme de vitesses de déformation est étudiée (de ε=10-4 s-1 à ε=102 s-1), à l’aide d’une machine de traction conventionnelle et d’une machine de traction à vitesses rapides. En regard des précautions qu’imposent les essais dynamiques, une investigation portant sur l’optimisation d’une géométrie d’éprouvette a été réalisée. Cette dernière assure la cohérence de l’identification des propriétés macroscopiques, ainsi que le respect de critères émanant de la littérature concernant les effets de forme et les phénomènes de propagation d’ondes de choc. Dans un second temps, afin de minimiser les oscillations dues au montage, un atténuateur d’ondes volumiques a été étudié à l’aide d’une simulation dynamique du montage d’essais. Les résultats révèlent une diminution de l’amplitude des oscillations de la force mesurée et une meilleure homogénéité des déformations dans la zone utile de l’éprouvette. Il en résulte une procédure robuste permettant d’aboutir à des données fiables et donc exploitables pour identifier un modèle

Towards a More Resilient Euro Area. Ideas from the 'Future Europe' Forum. CEPS Paperback, 18 June 2018

Much progress has been made in improving resilience of the single currency since the beginning of the crisis. But many important issues remain to be tackled. The leaders of euro-area member states are expected to use the European Union Summit on 28-29 June 2018 to take preliminary decisions about which additional reforms to pursue. The run-up to this meeting saw a lively debate involving economists and policymakers, albeit against a backdrop of rising Euroscepticism among and waning trust between European partners. ESMT and the German Council of Economic Experts (GCEE) initiated the ‘Future Europe’ forum in the summer of 2017, aiming to bring together a high-level group of economists to discuss economically sensible, legally sound, and politically feasible concepts that deserved to be taken forward. By offering a forum for discussion, we hoped to foster constructive dialogue. They chose an innovative video-conference format to bring experts together face to face without them having to leave their desks (or living rooms). Some 30 economists took part in a dozen such virtual meetings, and their contributions culminated in a publication, brought out jointly by the Centre for European Policy Studies (CEPS), ESMT and the GCEE. The ebookTowards a More Resilient Euro Area: Ideas from the ‘Future Europe’ forum gathers summaries of these economists’ proposals and the discussions they sparked. The main aim was not to produce a variant of the jointly-authored academic paper, but to foster a lively debate between economists who – as one participant put it – “agree somewhat, but not too much”. The publication as a result combines essays outlining an individual author’s thoughts with summaries of the informed, impassioned, and always respectful discussions during each forum. While each contribution can only be attributed to the respective author, each idea and thought is a valuable input that deserves to be considered by European governments as they set about the next euro-area reforms

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE