875 research outputs found
A novel technique for the measurement of the electron neutrino cross section
Absolute neutrino cross section measurements are presently limited by
uncertainties on fluxes. In this paper, we propose a technique that is
based on the reconstruction of large angle positrons in the decay tunnel to
identify three-body semileptonic decays. This
tagging facility operated in positron counting mode ("event count mode") can be
employed to determine the absolute flux at the neutrino detector with
precision. Facilities operated in "event by event tag mode"
i.e. tagged neutrino beams that exploit the time coincidence of the positron at
source and the interaction at the detector, are also discussed.Comment: 23 pages, 7 figures. Version to appear in EPJ
A compact light readout system for longitudinally segmented shashlik calorimeters
The longitudinal segmentation of shashlik calorimeters is challenged by dead
zones and non-uniformities introduced by the light collection and readout
system. This limitation can be overcome by direct fiber-photosensor coupling,
avoiding routing and bundling of the wavelength shifter fibers and embedding
ultra-compact photosensors (SiPMs) in the bulk of the calorimeter. We present
the first experimental test of this readout scheme performed at the CERN PS-T9
beamline in 2015 with negative particles in the 1-5~GeV energy range. In this
paper, we demonstrate that the scheme does not compromise the energy resolution
and linearity compared with standard light collection and readout systems. In
addition, we study the performance of the calorimeter for partially contained
charged hadrons to assess the separation capability and the response of
the photosensors to direct ionization.Comment: To appear in Nuclear Instruments and Methods in Physics Research,
Evaluation of basal ganglia haemodynamic changes with perfusion-weighted magnetic resonance imaging in patients with Parkinson's disease
The aim of our study was to assess the regional cerebral blood flow (rCBF) of basal ganglia and thalami in patients with Parkinson’s disease (PD) using perfusion–weighted magnetic resonance imaging (PW–MRI)
Suppression of flavor violation in an A4 warped extra dimensional model
In an attempt to simultaneously explain the observed masses and mixing
patterns of both quarks and leptons, we recently proposed a model
(JHEP08(2010)115) based on the non abelian discrete flavor group A4,
implemented in a custodial RS setup with a bulk Higgs. We showed that the
standard model flavor structure can be realized within the zero mode
approximation (ZMA), with nearly tribimaximal (TBM) neutrino mixing and a
realistic CKM matrix with rather mild assumptions. An important advantage of
this framework with respect to flavor anarchic models is the vanishing of the
dangerous tree level KK gluon contribution to \epsilon_K and the suppression of
the new physics one loop contributions to the neutron EDM, \epsilon'/\epsilon,
b->s\gamma and Higgs mediated flavor changing neutral current (FCNC) processes.
These results are obtained beyond the ZMA, in order to account for the the full
flavor structure and mixing of the zero modes and first Kaluza-Klein (KK) modes
of all generations. The resulting constraints on the KK mass scale are shown to
be significantly relaxed compared to the flavor anarchic case, showing
explicitly the role of non abelian discrete flavor symmetries in relaxing
flavor violation bounds within the RS setup. As a byproduct of our analysis we
also obtain the same contributions for the custodial anarchic case with two
SU(2)_R doublets for each fermion generation.Comment: 8 pages, 4 figures; contribution prepared for DISCRETE'10 - Symposium
on Prospects in the Physics of Discrete Symmetrie
Response of a radiology department to the SARS-CoV-2 pandemic: the experience of the hospital “Policlinico Tor Vergata” in Rome
The dissemination of severe acute respiratory syndrome linked to the novel coronavirus, SARS-CoV-2, prompted all health services to provide adequate measures to limit new cases that could affect healthcare professionals. Due to the large number of suspected patients subjected to CT scans and the proximity of radiologists to the patient during exams, radiologists as well as the entire staff of the radiology department are particularly exposed to SARS-CoV-2. This article includes the emergency management procedures, the use of personal protective devices, and the rearrangement of exam rooms and of human resources in the department of radiology at “Policlinico Tor Vergata” in Rome performed during the SARS-CoV-2 pandemic. We introduce the management measures that our department has taken to cope with the influx of patients while still ensuring the proper management of other emergencies and time-sensitive exams
Electron neutrino tagging through tertiary lepton detection
We discuss an experimental technique aimed at tagging electron neutrinos in
multi-GeV artificial sources on an event-by-event basis. It exploits in a novel
manner calorimetric and tracking technologies developed in the framework of the
LHC experiments and of rare kaon decay searches. The setup is suited for
slow-extraction, moderate power beams and it is based on an instrumented decay
tunnel equipped with tagging units that intercept secondary and tertiary
leptons from the bulk of undecayed \pi^+ and protons. We show that the taggers
are able to reduce the \nue contamination originating from K_e3 decays by about
one order of magnitude. Only a limited suppression (~60%) is achieved for \nue
produced by the decay-in-flight of muons; for low beam powers, similar
performance as for K_e3 can be reached supplementing the tagging system with an
instrumented beam dump.Comment: 19 pages, 7 figures; minor changes, version to appear in EPJ
Discovery of three new pulsars in a 610 MHz pulsar survey with the GMRT
We report on the discovery of three new pulsars in the first blind survey of
the north Galactic plane (45 degrees < l < 135 degrees; |b| < 1 degrees with
the Giant Meterwave Radio telescope (GMRT) at an intermediate frequency of 610
MHz. The survey covered 106 square degrees with a sensitivity of roughly 1 mJy
to long-period pulsars (pulsars with period longer than 1 s). The three new
pulsars have periods of 318, 933, and 1056 ms. Their timing parameters and flux
densities, obtained in follow up observations with the Lovell Telescope at
Jodrell Bank and the GMRT, are presented. We also report on pulse nulling
behaviour in one of the newly discovered pulsars, PSR J2208+5500.Comment: Accepted for publication in MNRAS, 7 pages, 5 figures, 2 table
A narrow band neutrino beam with high precision flux measurements
The ENUBET facility is a proposed narrow band neutrino beam where lepton
production is monitored at single particle level in the instrumented decay
tunnel. This facility addresses simultaneously the two most important
challenges for the next generation of cross section experiments: a superior
control of the flux and flavor composition at source and a high level of
tunability and precision in the selection of the energy of the outcoming
neutrinos. We report here the latest results in the development and test of the
instrumentation for the decay tunnel. Special emphasis is given to irradiation
tests of the photo-sensors performed at INFN-LNL and CERN in 2017 and to the
first application of polysiloxane-based scintillators in high energy physics.Comment: Poster presented at NuPhys2017 (London, 20-22 December 2017). 5
pages, 2 figure
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