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The INFN R&D: New pixel detector for the High Luminosity upgrade of the LHC
Get PDFThe High Luminosity upgrade of the CERN-LHC (HL-LHC) demands for a new high-radiation tolerant solid-state pixel sensor capable of surviving fluencies up to a few 1016 particles/cm2 at ∼3 cm from the interaction point. To
this extent the INFN ATLAS-CMS joint research activity, in collaboration with Fondazione Bruno Kessler-FBK, is aiming at the development of thin n-in-p type pixel sensors for the HL-LHC. The R&D covers both planar and single-sided 3D
columnar pixel devices made with the Si-Si Direct Wafer Bonding technique, which allows for the production of sensors with 100 μm and 130 μm active thickness for planar sensors, and 130 μm for 3D sensors, the thinnest ones ever produced so far. The first prototypes of hybrid modules bump-bonded to the present CMS and ATLAS readout chips have been tested in beam tests. The preliminary results on their performance before and after irradiation are presented
Test beam results with prototypes for the new Cylindrical GEM Inner Tracker of the BESIII experiment
Get PDFA cylindrical GEM tracker is under construction in order to replace and improve the inner tracking system of the BESIII experiment. Tests with planar chamber prototypes were carried out on the H4 beam line of SPS (CERN) with
muons of 150 GeV/c momentum, to evaluate the efficiency and resolution under different working conditions. The obtained efficiency was in the 96–98% range. Two complementary algorithms for the position determination were developed: the charge centroid and the μ-TPC methods. With the former, resolutions < 100 μm and < 200 μm were achieved without and with magnetic field, respectively. The μTPC improved these results. By the end of 2016, the first cylindrical prototype was tested on the same beam line. It showed optimal stability under different settings. The comparison of its performance with respect to the planar chambers is ongoing. Here, the results of the planar prototype tests will be addressed
A new approach for almost automatic installation of elastic cloud infrastructures
Get PDFIn the context of the cloud infrastructures at the INFN computing center of Torino, we implemented new simplified tools based up on OpenNebula cloud manager for almost automatic deployment of standard cloud infrastructure,
monitoring, maintenance, and VMs management within elastic cloud infrastructures. Such new tools for small and medium infrastructures could significantly improve their usability and efficiency by simplifying the installation and set up processes, providing easier access to elastic cloud technologies to sites with limited specific knowledge or dedicated manpower; introducing flexibility in a dynamic allocation of resources to the different stakeholders in one single infrastructure, maximizing the efficiency
The upgrade of the Inner Tracking System of the ALICE experiment
Get PDFIn 2021, for the third run of the CERN Large Hadron Collider (LHC), Pb-Pb collisions will be performed at a centre-of-mass energy per nucleon of 5.5 TeV, with an integrated luminosity of 6×1027 cm−2s −1 and at an unprecedented interaction rate up to 50 kHz. To fulfil the requirements of the ALICE physics program for Run 3, the ALICE experiment at LHC is planning a major upgrade during the Long Shutdown 2 of LHC in 2019–2020. One of the key elements, is the construction of a new ultra-light and high-resolution Inner Tracking System (ITS) to enhance the determination of the distance of closest approach to the primary vertex, the tracking efficiency at low transverse momenta, and the read-out rate capabilities, with respect to what can be achieved with the current detector. It will consist of seven layers equipped with silicon Monolithic Active Pixel Sensors (MAPS) with a pixel size of the order of 30 × 30 μm2 built with the Towerjazz 0.18 μm CMOS
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Time-evolution and dynamics of Floquet edge states in irradiated graphene nanoribbons
Get PDFWe study the solution of the time-dependent Schr¨odinger equation for systems driven out of equilibrium by a time-periodic laser field, using the Floquet equation as a mathematical tool to efficiently obtain the desired time-dependent observables. We calculate the velocity and charge of occupied states in a laserirradiated zig-zag graphene nanoribbon (zGNR), focusing on the role and properties of topologically protected edge states: their robustness against defects and disorder is tested, as well as their behavior when a bias voltage is applied across a section of the ribbon. Our results reveal the importance of the time-dependent approach to correctly calculate observables of laser-driven materials according to the occupation of states, suggesting how the properties of protected edge-states can be exploited to create flying-qubit architectures
GABAA receptor modulation by the Antisecretory Factor on cerebellar granule cells
Get PDFThe Antisecretory Factor (AF, Mw 41kD) is an endogenous protein, found in all mammalian tissues. AF acts in vivo by counteracting intestinal hypersecretion and various forms of inflammations. The detailed in vitro AF action on the cellular level is unknown. Using an in vitro neuronal model (granular cells from rat small brain) we studied AF action on ionotropic GABAA receptors. A facilitatory
activity, due to increased GABAA receptors expression, was demonstrated on the neuronal plasma membrane in response to AF influence. This effect may result in inhibition of intestinal secretomotor cells
Lepton-flavour universality tests at LHCb
Get PDFThe Standard Model predictions about the universality of the gauge boson couplings to charged leptons have been tested in B meson semileptonic decays. Several measurements of charged-current and neutral current processes were performed with a data sample collected with the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1. This review presents recent results that manifest some anomalies challenging the SM paradigm. Prospects for future measurements to elucidate the origin of these anomalies are also discussed
Measurements and combination of sin2θlept eff at the Tevatron
Get PDFWe present the combination of measurements of the effective-leptonic weak mixing angle parameter sin2θlept eff from the CDF and D0 experiments using the full Tevatron data sets. The standard model weak mixing angle parameter sin2θW and equivalent value of MW are inferred based on zfitter calculations. These Tevatron measurements are consistent with the world-best measurements from electron-positron colliders. The uncertainties represent the best precision from hadron colliders, nearly matching that of the best electron-positron individual measurements
LCP Fast Emission vs. Evaporation from 46Ti∗
Get PDFThe study of pre-equilibrium (or fast) emitted particles is a useful tool to examine nuclear clustering; to study how possible cluster structures affect nuclear reactions, the NUCL-EX Collaboration (INFN, Italy) is carrying out an extensive research campaign on pre-equilibrium emission of light charged particles from hot nuclei. In this framework, the reactions 16O+30Si, 18O+28Si and 19F + 27Al at 7MeV/u have been measured at the GARFIELD+RCo array in Legnaro National Laboratories. After a general introduction on the experimental campaign, this contribution will focus on the analysis results obtained so far; effects related to the entrance channel and to the colliding ions cluster nature are emphasized through differences between the theoretical predictions and the experimental data
How nuclear jets form and disintegrate into clusters in heavy-ion collisions
Get PDFThe most extreme deformations that can be explored in heavy-ion collisions at Fermi energies are collimated flows of nuclear matter which recall jet dynamics. From microphysics to the cosmological scale, jets are rather common topologies. In nuclear physics, pioneering works focused on the breakup of these structures, resulting in early nuclear-fission models in analogy with the droplet formation in viscous liquids; such view became emblematic to explain surface-energy effects and surface instability by analogy with the Rayleigh instability. Through a dynamical approach based on the Boltzmann-Langevin equation, well adapted to out-of-equilibrium conditions, we explored the possibility that nuclear jets could arise in heavy-ion collisions from different conditions than those leading to fission or neck fragmentation, and that they can breakup from mechanisms that are almost unrelated to cohesive properties