On the critical end point of the QCD and the NJL model phase diagrams

In this talk I compare the knowledge on the critical end point of the QCD phase diagram grasped from lattice calculations, with that obtained from Nambu--Jona-Lasinio (NJL) model computations. The original publication is available at http://www.sif.it/SIF/en/portal/journalsComment: 6 pages, 1 figure. Talk given at IFAE 2009, Bari, 15-17 April 2009. The original publication is available at: http://www.sif.it/SIF/en/portal/journal

The Critical End Point of Quantum Chromodynamics Detected by Chirally Imbalanced Quark Matter

We suggest the idea, supported by concrete calculations within chiral models, that the critical endpoint of the phase diagram of Quantum Chromodynamics with three colors can be detected, by means of Lattice simulations of grand-canonical ensembles with a chiral chemical potential, $\mu_5$, conjugated to chiral charge density. In fact, we show that a continuation of the critical endpoint of the phase diagram of Quantum Chromodynamics at finite chemical potential, $\mu$, to a critical end point in the temperature-chiral chemical potential plane, is possible. This study paves the way of the mapping of the phases of Quantum Chromodynamics at finite $\mu$, by means of the phases of a fictitious theory in which $\mu$ is replaced by $\mu_5$.Comment: List of changes: some reference added; chiral chemical potential better explained. Version to appear on Phys. Rev.

Chiral symmetry restoration and deconfinement in strong magnetic fields

I review recent results obtained within chiral effective models, on the phase structure of hot quark matter in a strong magnetic background. After a brief introduction, I focus on the results obtained within two chiral models improved with the Polyakov loop. The models differ for the content of interactions, but both of them are tuned to reproduce Lattice QCD thermodynamics at zero and imaginary chemical potential. One of them takes into account an explicit Polyakov loop dependence of the coupling; the other one neglects this contribution, but takes into account multi-quark interactions. A comparison between the phase diagrams of the two models is presented.Comment: 10 pages, 3 figures, PoS style. Invited talk at "The many faces of QCD, November 2-5, 2010, Gent, Belgium

Phase diagram of hot quark matter under magnetic field

In this talk, I review the computation of the phase diagram of hot quark matter in strong magnetic field, at zero baryon density, within an effective model of Quantum Chromodynamics.Comment: 5 pages; 2 figures. Talk given at "QCD@Work2010", 2010 June 20-23, Martina Franca, Ital

Diffusion of charm and beauty in the Glasma

Relativistic nuclear collisions offer a unique way to study strong interactions at very high energy. The collision process can be described within the gluon saturation framework as the interaction of two colored glasses, and because of this interaction strong longitudinal gluon fields, namely the Glasma, are produced immediately after the collision. Besides, heavy quarks are also produced in the very early stage and because of their large mass and small concentration, their motion does not affect the evolution of the Glasma, thus behaving as ideal probes of the Glasma itself. We study the evolution of the heavy quarks in the Glasma allegedly produced in high energy p-Pb collisions by solving consistently the equations of motion of the quarks in the evolving Glasma fields. We find that this motion can be understood in terms of diffusion in momentum space, similarly to the random motion of a heavy probe in a hot thermalized medium. We show how the diffusion of heavy probes affects the nuclear modification factor of D and B mesons in p-Pb collisions.Comment: Talk given by M. R. at QCD@Work2018 held in Matera, Italy, 25-28 June 201

Rheological Behavior of Microemulsions

We study the stationary and transient behaviors of the microemulsion phase subjected to a shear flow. The system is described by a diffusion-convective equation which generalizes the usual Cahn-Hilliard equation. Non-linear terms are treated in a self-consistent approximation. Shear, first and second normal stresses are calculated as momenta of the structure factor. Shear thinning is observed in stationary conditions. After a newtonian regime at small values of the shear rate, the excess viscosity decreases when the shear rate becomes of the order of the inverse of the relaxation time of the system without flow. In transient regimes, when the flow is applied starting from a quiescent state, we find that the shear stress reaches a maximum before decreasing to a constant value.Comment: 10 figures, 2 of which have format jp

Car Sharing and Relocation Strategies: a Case Study Comparison in the Italian Market

The sharing economy represents an economic model based on the sharing of goods and services. In particular, this paper examines car sharing model, an attractive alternative to a self-owned car which has found large interest in the recent literature in different research fields. This study aims to investigate innovative and effective relocation strategies based on the analysis of data on users’ consumptions, for the constantly growing car sharing system. For this purpose, after a literature review, the paper presents a case study focused on the car repositioning algorithm developed by one of the market leader in this sector: car2go. More in detail, the paper evaluates differences and similarities in the strategic management of this model within the Italian context, through a comparison among the cities of Rome and Milan. Empirical results and practical implications for users will be provided, by highlighting opportunities and threats concerning the different settings