1,974 research outputs found
DAMPE space mission: first data
The DAMPE (DArk Matter Particle Explorer) satellite was launched on December
17, 2015 and started its data taking operation a few days later.
DAMPE has a large geometric factor () and provides good
tracking, calorimetric and charge measurements for electrons, gammas rays and
nuclei. This will allow precise measurement of cosmic ray spectra from tens of
up to about . In particular, the energy region between $1-100\
TeVGeVTeV$, thus giving the opportunity to identify possible contribution
of nearby sources. A report on the mission goals and status is presented,
together with the on-orbit detector performance and the first data coming from
space.Comment: XXV ECRS 2016 Proceedings - eConf C16-09-04.
Model pseudofermionic systems: connections with exceptional points
We discuss the role of pseudo-fermions in the analysis of some
two-dimensional models, recently introduced in connection with non self-adjoint
hamiltonians. Among other aspects, we discuss the appearance of exceptional
points in connection with the validity of the extended anti-commutation rules
which define the pseudo-fermionic structure.Comment: in press in Phys. Rev.
Modeling interactions between political parties and electors
In this paper we extend some recent results on an operatorial approach to the
description of alliances between political parties interacting among themselves
and with a basin of electors. In particular, we propose and compare three
different models, deducing the dynamics of their related {\em decision
functions}, i.e. the attitude of each party to form or not an alliance. In the
first model the interactions between each party and their electors are
considered. We show that these interactions drive the decision functions
towards certain asymptotic values depending on the electors only: this is the
{\em perfect party}, which behaves following the electors' suggestions. The
second model is an extension of the first one in which we include a
which modifies the status of the electors, and of the decision functions as a
consequence, at some specific time step. In the third model we neglect the
interactions with the electors while we consider cubic and quartic interactions
between the parties and we show that we get (slightly oscillating) asymptotic
values for the decision functions, close to their initial values. This is the
{\em real party}, which does not listen to the electors. Several explicit
situations are considered in details and numerical results are also shown.Comment: To appear in Physica
Coordinate representation for non Hermitian position and momentum operators
In this paper we undertake an analysis of the eigenstates of two non
self-adjoint operators and similar, in a suitable sense, to
the self-adjoint position and momentum operators and
usually adopted in ordinary quantum mechanics. In particular we discuss
conditions for these eigenstates to be {\em biorthogonal distributions}, and we
discuss few of their properties. We illustrate our results with two examples,
one in which the similarity map between the self-adjoint and the non
self-adjoint is bounded, with bounded inverse, and the other in which this is
not true. We also briefly propose an alternative strategy to deal with
and , based on the so-called {\em quasi *-algebras}.Comment: Accepted in Proceedings of the Royal Society
Complex singularities and PDEs
In this paper we give a review on the computational methods used to
characterize the complex singularities developed by some relevant PDEs. We
begin by reviewing the singularity tracking method based on the analysis of the
Fourier spectrum. We then introduce other methods generally used to detect the
hidden singularities. In particular we show some applications of the Pad\'e
approximation, of the Kida method, and of Borel-Polya method. We apply these
techniques to the study of the singularity formation of some nonlinear
dispersive and dissipative one dimensional PDE of the 2D Prandtl equation, of
the 2D KP equation, and to Navier-Stokes equation for high Reynolds number
incompressible flows in the case of interaction with rigid boundaries
Dynamics for a quantum parliament
In this paper we propose a dynamical approach based on the
Gorini-Kossakowski-Sudarshan-Lindblad equation for a problem of decision
making. More specifically, we consider what was recently called a quantum
parliament, asked to approve or not a certain law, and we propose a model of
the connections between the various members of the parliament, proposing in
particular some special form of the interactions giving rise to a {\em
collaborative} or non collaborative behaviour
NICU Infants & SNHL: Experience of a western Sicily tertiary care centre
Introduction: The variability of symptoms and signs caused by central nervous system (CNS) lesions make multiple sclerosis difficult to recognize,Introduction: This study adds the evaluation of the independent etiologic factors that may play a role in the development of SNHL in a NICU population. We compared neonatal intensive care unit NICU infants with sensorineural hearing loss SNHL to age and gender matched normal hearing NICU controls. Materials and methods: 284 consecutive NICU infants positive to the presence of risk indicators associated with permanent congenital, delayed-onset, or progressive hearing loss underwent to global audiological assessment. The following risk factors were researched, making a distinction between prenatal and perinatal risk factors: in the first group, family history of permanent childhood hearing impairment, consanguinity, pregnant maternal infection and drugs exposition during pregnancy; in the second group, premature birth, respiratory distress, hyperbilirubinemia requiring exchange tranfusion, very low birth weight, cranio-facial abnormality, perinatal infections, ototoxic drugs administration, acidosis, hyponatremia, head trauma. Results: The analysis of the auditory deficit for infants according to numbers of risk factors showed mean values of: 78 + 28.08 dB nHL for infants positive to two risk factors; 75.71 + 30.30 dB nHL in cases positive to three risk factors; 96.66 + 34.46 dB nHL for four risk factors and 85 + 35 dB nHL in case of >5 risk factors. Conclusion: NICU infants have greater chances of developing SNHL, because of the presence of multiple risk factors; in fact, as the number of coexisting risk factors increases, the prevalence rate of SNHL also increases (r=0.81)
Study of neutron-rich calcium isotopes with a realistic shell-model interaction
We have studied neutron-rich calcium isotopes in terms of the shell model
employing a realistic effective interaction derived from the CD-Bonn
nucleon-nucleon potential. The short-range repulsion of the potential is
renormalized by way of the V-low-k approach. The calculated results are in very
good agreement with the available experimental data, thus supporting our
predictions for the hitherto unknown spectra of 53-56Ca nuclei. In this
context, the possible existence of an N=34 shell closure is discussed.Comment: 11 pages, 3 figures, to be published in Physical Review
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