323,362 research outputs found
Preface
No full textPREFACE
The second edition of the International Workshop on “Flavour changing and conserving processes” 2017 (FCCP2017) took place on September 7-9, 2017 in Anacapri, Capri Island, Italy. The Workshop was organized by the Physics Department of the University of Naples “Federico II” and by INFN (Istituto Nazionale di Fisica Nucleare) – Sezione di Napoli. The focus has still been continued on the physics of flavour changing and conserving processes, the involved scientific community has been that of experiments like g−2, Mu2e, MEG, Mu3e, COMET, but also that of the K and B meson physics. More than thirty talks were presented covering the theory status as well as the latest results of experiments in various Laboratories of the world. We wish to thank everybody who contributed to the success of the Workshop. The speakers did an excellent job in presenting the latest results and all participants contributed to the success of the Workshop. We look forward to the next edition FCCP2019 when new results are expected, from many sides, especially on the g-2 FRONT.
Giancarlo D’Ambrosio Michele Iacovacci Massimo Passera Graziano Venanzoni Stefano Mastroianni
Editors FCCP201
Motif formation and emergence of mesoscopic structure in complex networks
No full textPhDNetwork structures can encode information from datasets that have a natural representation
in terms of networks, for example datasets describing collaborations or social
relations among individuals in science or society, as well as from data that can be mapped
into graphs due to their intrinsic correlations, such as time series or images. Developing
models and algorithms to characterise the structure of complex networks at the micro
and mesoscale is thus of fundamental importance to extract relevant information from
and to understand real world complex data and systems. In this thesis we will investigate
how modularity, a mesoscopic feature observed almost universally in real world
complex networks can emerge, and how this phenomenon is related to the appearance of
a particular type of network motif, the triad. We will shed light on the role that motifs
play in shaping the mesoscale structure of complex networks by considering two special
classes of networks, multiplex networks, that describe complex systems where interactions
of different nature are involved, and visibility graphs, a family of graphs that can
be extracted from the time series of dynamical processes. This thesis is based on the
research papers listed below, in particular on the first five, published between 2014 and
2016:
1. Bianconi, G., Darst R. K., Iacovacci J., Fortunato S., Triadic closure as a basic generating
mechanism of communities in complex networks, Phys. Rev. E 90 (4), 042806
(2014).
2. Iacovacci J., Wu Z., Bianconi G., Mesoscopic structures reveal the network between
the layers of multiplex data sets, Phys. Rev. E. 92 (4), 042806 (2015).
3. Battiston F., Iacovacci J., Nicosia V., Bianconi G., Latora V., Emergence of multiplex
communities in collaboration networks, PloS one 11 (1), e0147451 (2016).
4. Iacovacci J., Lacasa L., Sequential visibility-graph motifs, Phys. Rev. E. 93 (4),
042309 (2016).
5. Iacovacci J., Lacasa L., Sequential motif pro le of natural visibility-graphs, Phys.
Rev. E. 94 (5), 052309 (2016).
6. Iacovacci J., Bianconi G., Extracting information from multiplex networks, Chaos:
An Interdisciplinary Journal of Nonlinear Science 26 (6), 065306 (2016).
7. Iacovacci J., Rahmede C., Arenas A., Bianconi G., Functional Multiplex PageRank,
EPL (Europhysics Letters) 116(2), 28004 (2016).
8. Lacasa L, Iacovacci J., Visibility graphs of random scalar elds and spatial data,
arXiv preprint arXiv:1702.07813 (2017).
9. Rahmede C, Iacovacci J, Arenas A, Bianconi G., Centralities of Nodes and In
infuences of Layers in Large Multiplex Network, arXiv preprint arXiv:1703.05833 (2017)
Online software time calibration for a continuous air shower array
No full textTime calibration is a crucial item for a shower array performance as it uses the time of flight method to reconstruct the arrival direction of the primary particle. This paper presents a software time calibration algorithm exploiting the continuous detector feature based on the assumption of locally flat shower front. On the small portions of the detector (tens of m2) a simple time-position fit of the arriving particles provides the time calibration constants of that part of detector. Then, a second step is needed to measure the time offset among the different portions obtaining the complete detector calibration. This algorithm is applied to ARGO-YBJ detector with a high trigger rate (several kHz) by means of an online processing and its performance is discussed
Online software time calibration for a continuous air shower array
No full textTime calibration is a crucial item for a shower array performance as it uses the time of flight method to reconstruct the arrival direction of the primary particle. This paper presents a software time calibration algorithm exploiting the continuous detector feature and based on the assumption of locally flat shower front; accordingly, taken a small portion of the detector (tens of ), a simple time-position fi t of the arriving particles provides the time calibration constants of that part of detector. In a second step, the time offsets among the different portions are measured and the complete detector calibration is obtained. The implementation of this algorithm in an online environment like the ARGO-YBJ data acquisition system has been studied. The results of this investigation are reported and discussed
Measurement of the proton-air inelastic cross section at root (s) approximate to 2 TeV from the EAS-TOP experiment
No full textThe proton-air inelastic cross section (σp-airinel) is measured at √s≈2 TeV at the EAS-TOP extensive air shower experiment by studying the absorption length of cosmic ray proton primaries cascades reaching the maximum development at the observation level. Primary energies, in the region E0=(1.5÷2.5)·10(15 ) eV, are selected through the EAS muon number (Nμ), and proton originated cascades at maximum development are selected by means of the shower size (Ne). The observed absorption length (λobs) is a convolution of the proton-air interaction length (λp-air) and of the shower and detector fluctuations. The conversion factor k=λobs/λint is obtained by means of simulations performed with the CORSIKA code and the QGSJET II and SIBYLL interaction models. The obtained value of the p-air inelastic cross section at √s≈2 TeV is σp-airinel=338±21(stat)±19(syst)-28(syst) mb. The statistical and systematic uncertainties, as well as the relationships with the pp (p̅ p) total cross section measurements are discussed
Triggerless DAQ system for a light based detector
No full textThe utilization of various types of photon detectors, generally referred to as light based detectors, is widespread in many fields of high energy physics, nuclear physics, astrophysics and medical imaging to measure scintillation photons or Cherenkov light. Both the traditional photomultiplier tubes (PMTs), still the most commonly used, and the silicon photomultipliers (SiPMs) in rapid development in the last years show good performance. The sensitivity down to single photoelectron (PE), the wide dynamic range and the fast timing characteristics can be exploited thanks to a careful optimization of the readout electronics, trigger and DAQ.
In applications where a high efficiency is required at low energy threshold (as for rare-event search experiments), in a typical trigger-based DAQ architecture, lowering the number of coincident signals for the event selection is mandatory with the consequent heavy increase of data rate that could not be sustained by the DAQ chain.
We have developed a triggerless data collection scheme for a light based detector that relies on a new generation of waveform digitizer board, developed by CAEN and able to manage an independent data acquisition on each channel. This paper describes the implementation and the performance of the triggerless DAQ system
Real-time imaging and tracking of microrobots in tissues using ultrasound phase analysis
No full textUltrasound B-mode imaging has been employed to monitor single agents and collective swarms of microrobots in vitro and ex vivo in controlled experimental conditions. However, low contrast and spatial resolution still limit the effective employment of such a method in a medical microrobotic scenario. Doppler-based ultrasound appears as a promising tool for tracking microrobots in echogenic and dynamic environments as biological tissues. In this Letter, we demonstrate that microrobot displacements can be used as a special signature for their visualization within echogenic media, where B-mode fails. To this aim, we induced vibrations of a magnetic soft microrobot through alternated magnetic fields and used ultrasound phase analysis to derive microrobot features such as size and position over time. By exploiting vibrations, we were able to perform imaging and tracking of a low contrast microrobot both in tissue-mimicking phantom and in chicken breast. The axial resolution was 38 μm, which is four times smaller than the B-mode resolution with the employed equipment. We also performed real-time tracking of the microrobot's positions along linear trajectories with a linear velocity up to 1 mm/s. Overall, the reported results pave the way for the application of the proposed approach for the robust monitoring of medical microrobots in tissue
A general estimator of the primary cosmic ray energy with the ARGO-YBJ experiment
No full textThe determination of the primary cosmic ray all-particle spectrum with ground-based air shower
experiments usually depends on the assumed elemental composition and hadronic interaction
model. Here we show that an energy estimator independent of the primary mass composition
can be defined by means of shower parameters measured in the core region, as carried out in
the ARGO-YBJ experiment. The energy resolution is <10% above 100 TeV and gets better with
energy increasing. Being insensitive to the number of muons, this energy determination has only
a weak dependence on the hadronic interaction model. The features of this energy estimator have
been validated by extensive MC simulations and used in the analysis of the ARGO-YBJ data
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