Results for "D. Gonnella"

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Steady State of microemulsions in shear flowApr 17 2000Steady-state properties of microemulsions in shear flow are studied in the context of a Ginzburg-Landau free-energy approach. Explicit expressions are given for the structure factor and the time correlation function at the one loop level of approximation. ... More
The Importance of the Electron Mean Free Path for Superconducting RF CavitiesJul 05 2016Aug 05 2016Impurity-doping is an exciting new technology in the field of SRF, producing cavities with record-high quality factor $Q_0$ and BCS surface resistance that decreases with increasing RF field. Recent theoretical work has offered a promising explanation ... More
Enhancement of structural rearrangement in glassy systems under shear flowNov 29 1999Feb 21 2001We extend the analysis of the mean field schematic model recently introduced for the description of glass forming liquids to the case of a supercooled fluid subjected to a shear flow of rate $\gamma$. After quenching the system to a low temperature $T$, ... More
Phase-ordering dynamics of binary mixtures with field-dependent mobility in shear flowApr 29 1999The effect of shear flow on the phase-ordering dynamics of a binary mixture with field-dependent mobility is investigated. The problem is addressed in the context of the time-dependent Ginzburg-Landau equation with an external velocity term, studied in ... More
Switching and defect dynamics in multistable liquid crystal devicesFeb 07 2011We investigate the switching dynamics of multistable nematic liquid crystal devices. In particular we identify a remarkably simple 2-dimensional (2D) device which exploits hybrid alignment at the surfaces to yield a bistable response. We also consider ... More
Bistable defect structures in blue phase devicesOct 28 2011Blue phases (BPs) are liquid crystals made up by networks of defects, or disclination lines. While existing phase diagrams show a striking variety of competing metastable topologies for these networks, very little is known as to how to kinetically reach ... More
Switching dynamics in cholesteric blue phasesMar 30 2011Blue phases are networks of disclination lines, which occur in cholesteric liquid crystals near the transition to the isotropic phase. They have recently been used for the new generation of fast switching liquid crystal displays. Here we study numerically ... More
A stochastic model of supercoiling-dependent transcriptionJun 21 2016Apr 13 2018We propose a stochastic model for gene transcription coupled to DNA supercoiling, where we incorporate the experimental observation that polymerases create supercoiling as they unwind the DNA helix, and that these enzymes bind more favourably to regions ... More
A stochastic model of supercoiling-dependent transcriptionJun 21 2016Jun 29 2016We propose a stochastic model for gene transcription coupled to DNA supercoiling, where we incorporate the experimental observation that polymerases create supercoiling as they unwind the DNA helix, and that these enzymes bind more favourably to regions ... More
The Phase Diagram of the Gonihedric 3d Ising Model via CVMJul 30 1996We use the cluster variation method (CVM) to investigate the phase structure of the 3d gonihedric Ising actions defined by Savvidy and Wegner. The geometrical spin cluster boundaries in these systems serve as models for the string worldsheets of the gonihedric ... More
Flexoelectric switching in cholesteric blue phasesMar 25 2013We present computer simulations of the response of a flexoelectric blue phase network, either in bulk or under confinement, to an applied field. We find a transition in the bulk between the blue phase I disclination network and a parallel array of disclinations ... More
FPGA-based Time to Digital Converter and Data Acquisition system for High Energy Tagger of KLOE-2 experimentMay 30 2012In order to reconstruct gamma-gamma physics events tagged with High Energy Tagger (HET) in the KLOE-2 (K LOng Experiment 2), we need to measure the Time Of Flight (TOF) of the electrons and positrons from the KLOE-2 Interaction Point (IP) to our tagging ... More
Lattice Boltzmann simulations of segregating binary fluid mixtures in shear flowMay 30 2000We apply lattice Boltzmann method to study the phase separation of a two-dimensional binary fluid mixture in shear flow. The algorithm can simulate systems described by the Navier-Stokes and convection-diffusion equations. We propose a new scheme for ... More
Low resource FPGA-based Time to Digital ConverterJun 04 2012Dec 08 2012Time to Digital Converters (TDCs) are very common devices in particles physics experiments. A lot of "off-the-shelf" TDCs can be employed but the necessity of a custom DAta acQuisition (DAQ) system makes the TDCs implemented on the Field-Programmable ... More
Computer simulations of domain growth in off-critical quenches of two-dimensional binary mixturesOct 08 2002The phase separation of two-dimensional binary mixtures has been studied through numerical Langevin simulations based on a Ginzburg-Landau free energy. We have considered not symmetric mixtures with and without imposed shear flow. In the sheared case ... More
Lattice Boltzmann Study of Velocity Behaviour in Binary Mixtures Under ShearMar 05 2003We apply lattice Boltzmann methods to study the relaxation of the velocity profile in binary fluids under shear during spinodal decomposition. In simple fluids, when a shear flow is applied on the boundaries of the system, the time required to obtain ... More
Rheological Behavior of MicroemulsionsOct 14 2002We 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 ... More
The KLOE-2 High Energy Tagger DetectorJun 04 2012In order to fully reconstruct to the reaction e+e- to e+e- gamma-gamma in the energy region of the phi meson production, new detectors along the DAFNE beam line have to be installed in order to detect the scattered e+e-. The High Energy Tagger (HET) detector ... More
Low RF power plasma ignition and detection for in-situ cleaning of 1.3 GHz 9-cell cavitiesFeb 08 2019Superconducting Radio Frequency (SRF) cavities performance preservation is crucial, from vertical test to accelerator operation. Field Emission (FE) is still one of the performance limiting factors to overcome and plasma cleaning has been proven successful ... More
Monte Carlo study of the phase transition in the Critical behavior of the Ising model with shearOct 16 2009The critical behavior of the Ising model with non-conserved dynamics and an external shear profile is analyzed by studying its dynamical evolution in the short time regime. Starting from high temperature disordered configurations (FDC), the critical temperature ... More
On the possibility to measure the (pi0 to gamma gamma) decay width and the (gamma* gamma to pi0) transition form factor with the KLOE-2 experimentSep 12 2011Feb 24 2012A possibility of KLOE-2 experiment to measure the width Gamma(pi0 to gamma gamma) and the (pi0 gamma gamma*) form factor F(Q^2) at low invariant masses of the virtual photon in the space-like region is considered. This measurement is an important test ... More
The Role of Magnetic Flux Expulsion to Reach Q0>3x10^10 in SRF CryomodulesDec 10 2018When a superconducting radiofrequency cavity is cooled through its critical temperature, ambient magnetic flux can become "frozen in" to the superconductor, resulting in degradation of the quality factor. This is especially problematic in applications ... More
Phases of active matter in two dimensionsOct 28 2018These notes focus on the description of the phases of matter in two dimensions. Firstly, we present a brief discussion of the phase diagrams of bidimensional interacting passive systems, and their numerical and experimental measurements. The presentation ... More
Phase-separation of binary fluids in shear flow: a numerical studySep 12 2000The phase-separation kinetics of binary fluids in shear flow is studied numerically in the framework of the continuum convection-diffusion equation based on a Ginzburg-Landau free energy. Simulations are carried out for different temperatures both in ... More
Two-scale competition in phase separation with shearApr 29 1999The behavior of a phase separating binary mixture in uniform shear flow is investigated by numerical simulations and in a renormalization group (RG) approach. Results show the simultaneous existence of domains of two characteristic scales. Stretching ... More
Spinodal decomposition to a lamellar phase: effects of hydrodynamic flowFeb 03 1997Results are presented for the kinetics of domain growth of a two-dimensional fluid quenched from a disordered to a lamellar phase. At early times when a Lifshitz-Slyozov mechanism is operative the growth process proceeds logarithmically in time to a frozen ... More
Time over threshold in the presence of noiseDec 04 2014The time over threshold is a widely used quantity to describe signals from various detectors in particle physics. Its electronics implementation is straightforward and in this paper we present the studies of its behavior in the presence of noise. A unique ... More
Pattern Formation in Liquid-Vapor Systems under Periodic Potential and ShearJul 25 2013May 28 2014In this paper the phase behavior and pattern formation in a sheared non-ideal fluid under a periodic potential is studied. An isothermal two-dimensional formulation of a lattice Boltzmann scheme for a liquid-vapor system with the van der Waals equation ... More
Thermal and hydrodynamic effects in the ordering of lamellar fluidsFeb 15 2011Phase separation in a complex fluid with lamellar order has been studied in the case of cold thermal fronts propagating diffusively from external walls. The velocity hydrodynamic modes are taken into account by coupling the convection-diffusion equation ... More
Heat fluctuations in Ising models coupled with two different heat bathsJul 02 2008Monte Carlo simulations of Ising models coupled to heat baths at two different temperatures are used to study a fluctuation relation for the heat exchanged between the two thermostats in a time $\tau$. Different kinetics (single--spin--flip or spin--exchange ... More
Lattice Boltzmann simulations of lamellar and droplet phasesJan 28 1998Lattice Boltzmann simulations are used to investigate spinodal decomposition in a two-dimensional binary fluid with equilibrium lamellar and droplet phases. We emphasise the importance of hydrodynamic flow to the phase separation kinetics. For mixtures ... More
Singular behavior of fluctuations in a relaxation processDec 09 2014Carrying out explicitly the computation in a paradigmatic model of non-interacting systems, the Gaussian Model, we show the existence of a singular point in the probability distribution $P(M)$ of an extensive variable $M$. Interpreting $P(M)$ as a thermodynamic ... More
Morphologies and flow patterns in quenching of lamellar systems with shearAug 01 2005We study the behavior of a fluid quenched from the disordered into the lamellar phase under the action of a shear flow. The dynamics of the system is described by Navier-Stokes and convection-diffusion equations with pressure tensor and chemical potential ... More
Spinodal decomposition of a binary mixture in an uniform shear flowJun 19 1998Results are presented for the phase separation process of a binary mixture subject to an uniform shear flow quenched from a disordered to a homogeneous ordered phase. The kinetics of the process is described in the context of the time-dependent Ginzburg-Landau ... More
Rotational and translational diffusion in an interacting active dumbbell systemJan 16 2015May 18 2015We study the dynamical properties of a two-dimensional ensemble of self-propelled dumbbells with only repulsive interactions. This model undergoes a phase transition between a homogeneous and a segregated phase and we focus on the former. We analyse the ... More
Six vertex model with domain-wall boundary conditions in the Bethe-Peierls approximationDec 22 2014We use the Bethe-Peierls method combined with the belief propagation algorithm to study the arctic curves in the six vertex model on a square lattice with domain-wall boundary conditions, and the six vertex model on a rectangular lattice with partial ... More
Phase separating binary fluids under oscillatory shearNov 05 2002We apply lattice Boltzmann methods to study the segregation of binary fluid mixtures under oscillatory shear flow in two dimensions. The algorithm allows to simulate systems whose dynamics is described by the Navier-Stokes and the convection-diffusion ... More
Ordering of the lamellar phase under a shear flowOct 08 2002The dynamics of a system quenched into a state with lamellar order and subject to an uniform shear flow is solved in the large-N limit. The description is based on the Brazovskii free-energy and the evolution follows a convection-diffusion equation. Lamellae ... More
A Lattice Boltzmann Model of Ternary Fluid MixturesJun 19 1998A lattice Boltzmann model is introduced which simulates oil-water-surfactant mixtures. The model is based on a Ginzburg-Landau free energy with two scalar order parameters. Diffusive and hydrodynamic transport is included. Results are presented showing ... More
The segregation of sheared binary fluids in the Bray-Humayun modelOct 08 2002The phase separation process which follows a sudden quench inside the coexistence region is considered for a binary fluid subjected to an applied shear flow. This issue is studied in the framework of the convection-diffusion equation based on a Ginzburg-Landau ... More
Renormalization Group results for lattice surface modelsJan 04 1995We study the phase diagram of statistical systems of closed and open interfaces built on a cubic lattice. Interacting closed interfaces can be written as Ising models, while open surfaces as Z(2) gauge systems. When the open surfaces reduce to closed ... More
Heat exchanges in coarsening systemsNov 02 2011This paper is a contribution to the understanding of the thermal properties of aging systems where statistically independent degrees of freedom with largely separated timescales are expected to coexist. Focusing on the prototypical case of quenched ferromagnets, ... More
Thermocurrents and their Role in high Q Cavity PerformanceNov 19 2014Jan 12 2015Over the past years it became evident that the quality factor of a superconducting cavity is not only determined by its surface preparation procedure, but is also influenced by the way the cavity is cooled down. Moreover, different data sets exists, some ... More
Structure and rheology of binary mixtures in shear flowJan 24 2000Results are presented for the phase separation process of a binary mixture subject to an uniform shear flow quenched from a disordered to a homogeneous ordered phase. The kinetics of the process is described in the context of the time-dependent Ginzburg-Landau ... More
Sensitivity of Niobium Superconducting Cavities to Trapped Magnetic Flux DissipationSep 14 2015Nov 24 2015Future particle accelerators such as the the SLAC ``Linac Coherent Light Source-II'' (LCLS-II) and the proposed Cornell Energy Recovery Linac (ERL) require hundreds of superconducting radio-frequency (SRF) cavities operating in continuous wave (CW) mode. ... More
Condensation of Fluctuations in and out of EquilibriumApr 15 2014Condensation of fluctuations is an interesting phenomenon conceptually distinct from condensation on average. One stricking feature is that, contrary to what happens on average, condensation of fluctuations may occurr even in the absence of interaction. ... More
Kinetics of self-induced aggregation in Brownian particlesMar 16 2007We study a model of interacting random walkers that proposes a simple mechanism for the emergence of cooperation in group of individuals. Each individual, represented by a Brownian particle, experiences an interaction produced by the local unbalance in ... More
Condensation and equilibration in an urn modelFeb 17 2015May 11 2015After reviewing the general scaling properties of aging systems, we present a numerical study of the slow evolution induced in the zeta urn model by a quench from a high temperature to a lower one where a condensed equilibrium phase exists. By considering ... More
Multi-scale control of active emulsion dynamicsJun 14 2019We numerically study the energy transfer in a multi-component $2d$ film, made of an active polar gel and a passive isotropic fluid in presence of surfactant favoring emulsification. We show that by confining the active behavior into the localized component, ... More
Fluctuations of rotational and translational degrees of freedom in an interacting active dumbbell systemApr 14 2015We study the dynamical properties of a two-dimensional ensemble of self-propelled dumbbells with only repulsive interactions. After summarizing the behavior of the translational and rotational mean-square displacements in the homogeneous phase that we ... More
Phase separation of incompressible binary fluids with Lattice Boltzmann MethodsSep 23 2003We introduce new versions of lattice Boltzmann methods (LBM) for incompressible binary mixtures where fluctuations of total density are inhibited. As a test for the improved algorithms we consider the problem of phase separation of two-dimensional binary ... More
A lattice Boltzmann study of phase separation in liquid-vapor systems with gravityJul 16 2009Phase separation of a two-dimensional van der Waals fluid subject to a gravitational force is studied by numerical simulations based on lattice Boltzmann methods (LBM) implemented with a finite difference scheme. A growth exponent $\alpha=1$ is measured ... More
Finite difference lattice Boltzmann model with flux limiters for liquid-vapor systemsJul 21 2004In this paper we apply a finite difference lattice Boltzmann model to study the phase separation in a two-dimensional liquid-vapor system. Spurious numerical effects in macroscopic equations are discussed and an appropriate numerical scheme involving ... More
Cavitation inception of a van der Waals fluid at a sack-wall obstacleMay 02 2016Cavitation in a liquid moving past a constraint is numerically investigated by means of a free-energy lattice Boltzmann simulation based on the van der Waals equation of state. The fluid is streamed past an obstacle and, depending on the pressure drop ... More
Monte Carlo study of the growth of striped domainsSep 11 1997We analyze the dynamical scaling behavior in a two-dimensional spin model with competing interactions after a quench to a striped phase. We measure the growth exponents studying the scaling of the interfaces and the scaling of the shrinking time of a ... More
Phase co-existence in bidimensional passive and active dumbbell systemsNov 21 2016We demonstrate that there is co-existence between hexatic order and liquid/gas phase over a finite interval of packing fractions in active repulsive dumbbell systems in two dimensions. In the passive limit this interval remains finite, similarly to what ... More
Folding transitions in three-dimensional space with defectsJan 07 2012May 24 2012A model describing the three-dimensional folding of the triangular lattice on the face-centered cubic lattice is generalized allowing the presence of defects corresponding to cuts in the two-dimensional network. The model can be expressed in terms of ... More
Phase co-existence in bidimensional passive and active dumbbell systemsNov 21 2016Nov 29 2017We demonstrate that there is macroscopic co-existence between regions with hexatic order and regions in the liquid/gas phase over a finite interval of packing fractions in active dumbbell systems with repulsive power-law interactions in two dimensions. ... More
Rheology of an inverted cholesteric droplet under shear flowJul 12 2018The dynamics of a quasi two-dimensional isotropic droplet in a cholesteric liquid crystal medium under symmetric shear flow is studied by lattice Boltzmann simulations. We consider a geometry in which the flow direction is along the axis of the cholesteric, ... More
Large fluctuations and dynamic phase transition in a system of self-propelled particlesOct 15 2017We study the statistics, in stationary conditions, of the work $W_\tau$ done by the active force in different systems of self-propelled particles in a time $\tau$. We show the existence of a critical value $W_\tau ^\dag$ such that fluctuations with $W_\tau ... More
Hybrid lattice Boltzmann model for binary fluid mixturesFeb 23 2009Jul 16 2009A hybrid lattice Boltzmann method (LBM) for binary mixtures based on the free-energy approach is proposed. Non-ideal terms of the pressure tensor are included as a body force in the LBM kinetic equations, used to simulate the continuity and Navier-Stokes ... More
Folding transitions of the square--diagonal two--dimensional latticeFeb 16 2000The phase diagram of a vertex model introduced by P. Di Francesco (Nucl. Phys. B 525, 507 1998) representing the configurations of a square lattice which can fold with different bending energies along the main axes and the diagonals has been studied by ... More
Energy and Heat Fluctuations in a Temperature QuenchSep 09 2014Fluctuations of energy and heat are investigated during the relaxation following the instantaneous temperature quench of an extended system. Results are obtained analytically for the Gaussian model and for the large $N$ model quenched below the critical ... More
Persistence exponent in a superantiferromagnetic quenchingSep 23 1998We measure the persistence exponent in a phase separating two-dimensional spin system with non-conserved dynamics quenched in a region with four coexisting stripe phases. The system is an Ising model with nearest neighbor, next-to-the-nearest neighbor ... More
Fluctuation relations in non-equilibrium stationary states of Ising modelsJan 15 2009Fluctuation relations for the entropy production in non equilibrium stationary states of Ising models are investigated by Monte Carlo simulations. Systems in contact with heat baths at two different temperatures or subject to external driving will be ... More
Anisotropic dynamical scaling in a spin model with competing interactionsMay 14 1997Results are presented for the kinetics of domain growth of a two-dimensional Ising spin model with competing interactions quenched from a disordered to a striped phase. The domain growth exponent are $\beta=1/2$ and $\beta=1/3$ for single-spin-flip and ... More
New critical behaviour of the three-dimensional Ising model with nearest-neighbor, next-nearest-neighbor and plaquette interactionsNov 29 1996The critical and multicritical behavior of the simple cubic Ising model with nearest-neighbor, next-nearest-neighbor and plaquette interactions is studied using the cube and star-cube approximations of the cluster variation method and the recently proposed ... More
Folding transitions of the triangular lattice with defectsJul 28 1995A recently introduced model describing the folding of the triangular lattice is generalized allowing for defects in the lattice and written as an Ising model with nearest-neighbor and plaquette interactions on the honeycomb lattice. Its phase diagram ... More
Critical behaviour of the three-dimensional gonihedric Ising ModelDec 23 1997We use the cluster variation method (CVM) and Monte Carlo simulations to investigate the phase structure of the 3d gonihedric Ising actions defined by Savvidy and Wegner. This model corresponds to the usual three-dimensional cubic Ising model with nearest, ... More
Effects of an external drive on the fluctuation-dissipation relation of phase-ordering systemsMay 29 2002The relation between the autocorrelation $C(t,t_w)$ and the integrated linear response function $\chi(t,t_w)$ is studied in the context of the large-N model for phase-ordering systems subjected to a shear flow. In the high temperature phase $T>T_c$ a ... More
Correlation Functions and Fluctuation-Dissipation Relation in Driven Mixtures: an exactly solvable modelOct 21 2002Oct 29 2002The dynamics of a binary system with non conserved order parameter under a plain shear flow with rate $\gamma $ is solved analytically in the large-N limit. A phase transition is observed at a critical temperature $T_c(\gamma)$. After a quench from a ... More
Strong anomalous diffusion of the phase of a chaotic pendulumApr 21 2015In this letter we consider the phase diffusion of a harmonically driven undamped pendulum and show that it is anomalous in the strong sense. The role played by the fractal properties of the phase space is highlighted, providing an illustration of the ... More
Correlation functions by Cluster Variation Method for Ising model with NN, NNN and Plaquette interactionsMay 12 1998We consider the procedure for calculating the pair correlation function in the context of the Cluster Variation Methods. As specific cases, we study the pair correlation function in the paramagnetic phase of the Ising model with nearest neighbors, next ... More
Folding transition of the triangular lattice in a discrete three--dimensional spaceDec 11 1995A vertex model introduced by M. Bowick, P. Di Francesco, O. Golinelli, and E. Guitter (cond-mat/9502063) describing the folding of the triangular lattice onto the face centered cubic lattice has been studied in the hexagon approximation of the cluster ... More
Phase separation of binary fluids with dynamic temperatureSep 20 2010Phase separation of binary fluids quenched by contact with cold external walls is considered. Navier-Stokes, convection-diffusion, and energy equations are solved by lattice Boltzmann method coupled with finite-difference schemes. At high viscosity, different ... More
Switching dynamics in cholesteric liquid crystal emulsionsJul 31 2017In this work we numerically study the switching dynamics of a 2D cholesteric emulsion droplet immersed in an isotropic fluid under an electric field, which is either uniform or rotating with constant speed. The overall dynamics depend strongly on the ... More
Motility-induced phase separation and coarsening in active matterFeb 08 2015May 18 2015Active systems, or active matter, are self-driven systems which live, or function, far from equilibrium - a paradigmatic example which we focus on here is provided by a suspension of self-motile particles. Active systems are far from equilibrium because ... More
Heat exchanges in a quenched ferromagnetNov 05 2012Jan 08 2013The off-equilibrium probability distribution of the heat exchanged by a ferromagnet in a time interval after a quench below the critical point is calculated analytically in the large-N limit. The distribution is characterized by a singular threshold Qc ... More
On superconducting niobium accelerating cavities fired under N2-gas exposureJul 11 2014May 28 2015The dependence of the Q-value on the RF field (Q-slope) is actively studied in various accelerator laboratories. Although remedies against this dependence have been found, the physical cause still remains obscure. A rather straightforward two-fluid model ... More
Scaling and hydrodynamic effects in lamellar orderingApr 08 2004Feb 03 2005We study the kinetics of domain growth of fluid mixtures quenched from a disordered to a lamellar phase. At low viscosities, in two dimensions, when hydrodynamic modes become important, dynamical scaling is verified in the form $C(\vec k, t) \sim L^{\alpha} ... More
The integrated low-level trigger and readout system of the CERN NA62 experimentMar 25 2019The integrated low-level trigger and data acquisition (TDAQ) system of the NA62 experiment at CERN is described. The requirements of a large and fast data reduction in a high-rate environment for a medium-scale, distributed ensemble of many different ... More
Active dumbbells: dynamics and morphology in the coexisting regionMay 17 2018Oct 06 2018With the help of molecular dynamics simulations we study an ensemble of active dumbbells in purely repulsive interaction. We derive the phase diagram in the density-activity plane and we characterise the various phases with liquid, hexatic and solid character. ... More
Transcriptional bursts in a non-equilibrium model for gene regulation by supercoilingApr 25 2019We analyse transcriptional bursting within a stochastic non-equilibrium model which accounts for the coupling between the dynamics of DNA supercoiling and gene transcription. We find a clear signature of bursty transcription when there is a separation ... More
Lattice Boltzmann Methods and Active FluidsJun 03 2019We review the state of the art of active fluids with particular attention to hydrodynamic continuous models and to the use of Lattice Boltzmann Methods (LBM) in this field. We present the thermodynamics of active fluids, in terms of liquid crystals modelling ... More
Study of the performance of the NA62 Small-Angle Calorimeter at the DA$Φ$NE LinacOct 12 2016The measurement of $BR(K^+\to\pi^+\nu\bar{\nu})$ with 10% precision by the NA62 experiment requires extreme background suppression. The Small Angle Calorimeter aims to provide an efficient veto for photons flying at angles down to zero with respect to ... More
Corner transport upwind lattice Boltzmann model for bubble cavitationFeb 05 2018Aiming to study the bubble cavitation problem in quiescent and sheared liquids, a third-order isothermal lattice Boltzmann (LB) model that describes a two-dimensional ($2D$) fluid obeying the van der Waals equation of state, is introduced. The evolution ... More
Prospects for $K^+ \to π^+ ν\bar{ ν}$ at CERN in NA62Nov 01 2014The NA62 experiment will begin taking data in 2015. Its primary purpose is a 10% measurement of the branching ratio of the ultrarare kaon decay $K^+ \to \pi^+ \nu \bar{ \nu }$, using the decay in flight of kaons in an unseparated beam with momentum 75 ... More
Lamellar ordering, droplet formation and phase inversion in exotic active emulsionsFeb 18 2018We study numerically the behaviour of a mixture of a passive isotropic fluid and an active polar gel, in the presence of a surfactant favouring emulsification. Focussing on parameters for which the underlying free energy favours the lamellar phase in ... More
Dynamics of a homogeneous active dumbbell systemAug 04 2014Oct 24 2014We analyse the dynamics of a two dimensional system of interacting active dumbbells. We characterise the mean-square displacement, linear response function and deviation from the equilibrium fluctuation-dissipation theorem as a function of activity strength, ... More
Response of Autonomic Nervous System to Body Positions: Fourier and Wavelet AnalysisOct 24 2003Mar 18 2005Two mathematical methods, the Fourier and wavelet transforms, were used to study the short term cardiovascular control system. Time series, picked from electrocardiogram and arterial blood pressure lasting 6 minutes, were analyzed in supine position (SUP), ... More
Comparison between isothermal collision-streaming and finite-difference lattice Boltzmann modelsApr 04 2019We present here a comparison between collision-streaming and finite-difference lattice Boltzmann (LB) models. This study provides a derivation of useful formulae which help one to properly compare the simulation results obtained with both LB models. We ... More
Morphology and flow patterns in highly asymmetric active emulsionsFeb 19 2019We investigate numerically, by a hybrid lattice Boltzmann method, the morphology and the dynamics of an emulsion made of a polar active gel, contractile or extensile, and an isotropic passive fluid. We focus on the case of a highly off-symmetric ratio ... More
Full phase diagram of active Brownian disks: from melting to motility-induced phase separationMay 31 2018Sep 14 2018We establish the complete phase diagram of self-propelled hard disks in two spatial dimensions from the analysis of the equation of state and the statistics of local order parameters. The equilibrium melting scenario is maintained at small activities, ... More
$γγ$ physics with the KLOE experimentJul 19 2011The processes $e^+e^-\to e^+e^-X$, with $X$ being either the $\eta$ meson or $\pi^0\pi^0$, are studied at DA$\Phi$NE, with $e^+e^-$ beams colliding at $\sqrt{s}\simeq1$ GeV, below the $\phi$ resonance peak. The data sample is from an integrated luminosity ... More
Measurement of Γ(η-> π^+π^-γ)/Γ(η-> π^+π^-π^0) with the KLOE DetectorSep 20 2012Nov 16 2012The ratio R_{\eta}=\Gamma(\eta -> \pi^+\pi^-\gamma)/\Gamma(\eta -> \pi^+\pi^-\pi^0) has been measured by analyzing 22 million \phi \to \eta \gamma decays collected by the KLOE experiment at DA\PhiNE, corresponding to an integrated luminosity of 558 pb^{-1}. ... More
A new limit on the CP violating decay KS -> 3pi0 with the KLOE experimentJan 31 2013May 19 2013We have carried out a new direct search for the CP violating decay KS -> 3pi0 with 1.7 fb^-1 of e+e- collisions collected by the KLOE detector at the phi-factory DAFNE. We have searched for this decay in a sample of about 5.9 x 10^8 KS KL events tagging ... More
U boson searches at KLOEJul 13 2011The existence of a secluded gauge sector could explain several puzzling astrophysical observations. This hypothesis can be tested at low energy e+e- colliders such as DAPHNE. Preliminary results obtained with KLOE data and perpectives for the KLOE-2 run, ... More
Measurement of η meson production in γγ interactions and Γ(η-->γγ) with the KLOE detectorNov 08 2012Dec 12 2012We present a measurement of {\eta} meson production in photon-photon interactions produced by electron-positron beams colliding with \sqrt{s}=1 GeV. The measurement is done with the KLOE detector at the \phi-factory DA{\Phi}NE with an integrated luminosity ... More
Limit on the production of a light vector gauge boson in phi meson decays with the KLOE detectorOct 15 2012Jan 31 2013We present a new limit on the production of a light dark-force mediator with the KLOE detector at DAPHNE. This boson, called U, has been searched for in the decay phi --> eta U, U --> e+ e-, analyzing the decay eta --> pi0 pi0 pi0 in a data sample of ... More
Neutrino oscillations along the Earth to probe flavor parameters: a NeuWorldJan 11 2013Mar 12 2013On 2010 MINOS experiment was showing an hint of possible different mass splitting and mixing angles for neutrinos and anti-neutrinos, suggesting a charge-parity-time (CPT) violation in the lepton sector; last year 2012 a second result from MINOS showed ... More