Prediction of charm-production fractions in neutrino interactions

The way a charm-quark fragments into a charmed hadron is a challenging problem both for the theoretical and the experimental particle physics. Moreover, in neutrino induced charm-production, peculiar processes occur such as quasi-elastic and diffractive charm-production which make the results from other experiments not directly comparable. We present here a method to extract the charmed fractions in neutrino induced events by using results from $e^+e^-$, $\pi N$, $\gamma N$ experiments while taking into account the peculiarities of charm-production in neutrino interactions. As results, we predict the fragmentation functions as a function of the neutrino energy and the semi-muonic branching ratio, $B_\mu$, and compare them with the available data

Study of defect formation in Al 7050 alloys

The Al 7050 alloy is an Al-Zn-Mg-Cu-Zr alloy having good mechanical properties. This alloy has been developed in order to overcome stress corrosion cracking problems that characterise 7xxx Al alloys. Despite Al 7050 is widely used for aerospace applications, it can be subjected to crack initiation and propagation during the manufacturing process. In this work cracked Al 7050 components have been analysed in order to identify possible causes of crack formation such as coarse intermetallic phase presence, voids or wrong mechanical machining processes

A search for Z' in muon neutrino associated charm production

In many extensions of the Standard Model the presence of an extra neutral boson, Z', is invoked. A precision study of weak neutral-current exchange processes involving only second generation fermions is still missing. We propose a search for Z' in muon neutrino associated charm production. This process only involves Z' couplings with fermions from the second generation. An experimental method is thoroughly described using an ideal detector. As an application, the accuracy reachable with present and future experiments has been estimated.Comment: 13 pages, 3 figures, late

SBV regularity for Hamilton-Jacobi equations in Rn\mathbb R^n

In this paper we study the regularity of viscosity solutions to the following Hamilton-Jacobi equations $$\partial_t u + H(D_{x} u)=0 \qquad \textrm{in} \Omega\subset \mathbb R\times \mathbb R^{n} .$$ In particular, under the assumption that the Hamiltonian $H\in C^2(\mathbb R^n)$ is uniformly convex, we prove that $D_{x}u$ and $\partial_t u$ belong to the class $SBV_{loc}(\Omega)$.Comment: 15 page

Directionality preservation of nuclear recoils in an emulsion detector for directional dark matter search

Nuclear emulsion is a well-known detector type proposed also for the directional detection of dark matter. In this paper, we study one of the most important properties of direction-sensitive detectors: the preservation by nuclear recoils of the direction of impinging dark matter particles. For nuclear emulsion detectors, it is the first detailed study where a realistic nuclear recoil energy distribution with all possible recoil atom types is exploited. Moreover, for the first time we study the granularity effect on the emulsion detector directional performance. As well as we compare nuclear emulsion with other directional detectors: in terms of direction preservation nuclear emulsion outperforms the other detectors for WIMP masses above 100 GeV/c$^2$.Comment: Prepared for submission to JCA

High-resolution tracking in a GEM-Emulsion detector

SHiP (Search for Hidden Particles) is a beam dump experiment proposed at the CERN SPS aiming at the observation of long lived particles very weakly coupled with ordinary matter mostly produced in the decay of charmed hadrons. The beam dump facility of SHiP is also a copious factory of neutrinos of all three kinds and therefore a dedicated neutrino detector is foreseen in the SHiP apparatus. The neutrino detector exploits the Emulsion Cloud Chamber technique with a modular structure, alternating walls of target units and planes of electronic detectors providing the time stamp to the event. GEM detectors are one of the possible choices for this task. This paper reports the results of the first exposure to a muon beam at CERN of a new hybrid chamber, obtained by coupling a GEM chamber and an emulsion detector. Thanks to the micrometric accuracy of the emulsion detector, the position resolution of the GEM chamber as a function of the particle inclination was evaluated in two configurations, with and without the magnetic fiel

On the concentration of entropy for scalar conservation laws

We prove that the entropy for an $L^\infty$-solution to a scalar conservation laws with continuous initial data is concentrated on a countably $1$-rectifiable set. To prove this result we introduce the notion of Lagrangian representation of the solution and give regularity estimates on the solution

A network model of Italy shows that intermittent regional strategies can alleviate the COVID-19 epidemic

The COVID-19 epidemic hit Italy particularly hard, yielding the implementation of strict national lockdown rules. Previous modelling studies at the national level overlooked the fact that Italy is divided into administrative regions which can independently oversee their own share of the Italian National Health Service. Here, we show that heterogeneity between regions is essential to understand the spread of the epidemic and to design effective strategies to control the disease. We model Italy as a network of regions and parameterize the model of each region on real data spanning over two months from the initial outbreak. We confirm the effectiveness at the regional level of the national lockdown strategy and propose coordinated regional interventions to prevent future national lockdowns, while avoiding saturation of the regional health systems and mitigating impact on costs. Our study and methodology can be easily extended to other levels of granularity to support policy- and decision-makers

Moving in unison after perceptual interruption

Humans interact in groups through various perception and action channels. The continuity of interaction despite a transient loss of perceptual contact often exists and contributes to goal achievement. Here, we study the dynamics of this continuity, in two experiments involving groups of participants (N= 7) synchronizing their movements in space and in time. We show that behavioural unison can be maintained after perceptual contact has been lost, for about 7s. Agent similarity and spatial configuration in the group modulated synchronization performance, differently so when perceptual interaction was present or when it was memorized. Modelling these data through a network of oscillators enabled us to clarify the double origin of this memory effect, of individual and social nature. These results shed new light into why humans continue to move in unison after perceptual interruption, and are consequential for a wide variety of applications at work, in art and in sport