High-energy astroparticle physics with CALET

The CALorimetric Electron Telescope (CALET) will be installed on the Exposure Facility of the Japanese Experiment Module (JEM-EF) on the International Space Station (ISS) in 2014 where it will measure the cosmic-ray fluxes for five years. Its main scientific goals are to search for dark matter, investigate the mechanism of cosmic-ray acceleration and propagation in the Galaxy and discover possible astrophysical sources of high-energy electrons nearby the Earth. The instrument, under construction, consists of two layers of segmented plastic scintillators for the cosmic-ray charge identification (CHD), a 3 X$_0$-thick tungsten-scintillating fiber imaging calorimeter (IMC) and a 27 X$_0$-thick lead-tungstate calorimeter (TASC). The CHD can provide single-element separation in the interval of atomic number Z from 1 to 40, while IMC and TASC can measure the energy of cosmic-ray particles with excellent resolution in the range from few GeV up to several hundreds of TeV. Moreover, IMC and TASC provide the longitudinal and lateral development of the shower, a key issue for good electron/hadron discrimination. In this paper, we will review the status of the mission, the instrument configuration and its expected performance, and the CALET capability to measure the different components of the cosmic radiation.Comment: 4 pages, 3 figures. Contribution to the proceedings for the 23rd European Cosmic Ray Symposium 3-7 July 2012, Moscow, Russi

Cosmic rays: direct measurements

This paper is based on the rapporteur talk given at the 34$^{th}$ International Cosmic Ray Conference (ICRC), on August 6$^{th}$, 2015. The purpose of the talk and paper is to provide a summary of the most recent results from balloon-borne and space-based experiments presented at the conference, and give an overview of the future missions and developments foreseen in this field.Comment: Write-up of the rapporteur talk given at the 34th International Cosmic Ray Conference, 30 July-6 August, 2015, The Hague, The Netherlands. 24 pages , 11 figure

Observation of charm mixing at CDF

We report on the observation of $D^0$--$\bar{D}^0$ oscillations by measuring the time-dependent ratio of yields for the rare decay $D^0 \rightarrow K^+\pi^-$ to the favored decay $D^0 \rightarrow K^-\pi^+$ at the Collider Detector at Fermilab (CDF). Using 9.6 fb$^{-1}$ of integrated luminosity of $\sqrt{s}$ = 1.96 TeV $p$$\bar{p}$ collisions recorded in the full CDF Run II, the signals of $7.6 \times 10^6$ $D^0\rightarrow K^-\pi^+$ and $33 \times 10^3$ $D^0\rightarrow K^+\pi^-$ decays are reconstructed in $D^{*}$-tagged events, with proper decay times between 0.75 and 10 mean $D^0$ lifetimes. We measure the mixing parameters $x'^2 = (0.08 \pm 0.18)\times 10^{-3}$, $y' = (4.3 \pm 4.3) \times 10^{-3}$, and $R_D = (3.51 \pm 0.35) \times 10^{-3}$. Our results are consistent with standard model expectations and similar results from proton-proton collisions and exclude the no-mixing hypothesis with a significance equivalent to 6.1 standard deviations.Comment: 6 pages, 7 figures, 1 table. Contribution to the proceedings for the 14th International Conference on B-Physics at Hadron Machines, April 8-12, 2013, Bologna, Ital

Rare decay searches at CDF

In the last decade the CDF experiment at the Tevatron clearly demonstrated that it is possible to study extensively heavy flavour physics in hadron collisions and achieve remarkable results, competitive and complementary to $B$-factories. In this paper we report on the indirect searches for physics beyond the standard model via measurements of rare $b$-hadron decays. The final limits, based on the analysis of the full CDF data set, on the branching fraction of the $B^0_{(s)}$ decay into a pair of muons are presented and discussed. Moreover we review the latest measurements, with 6.8 fb$^{-1}$ of collected data, of the total and differential branching fractions and angular observables of rare $b$-hadron decays proceeding via the flavour-changing neutral-current process $b \rightarrow s \mu^+ \mu^-$. PACS numbers: 13.20.He, 13.30.-a, 12.15.M

CALET on the International Space Station: a precise measurement of the iron spectrum

The Calorimetric Electron Telescope (CALET) was launched on the International Space Station in 2015 and since then has collected a large sample of cosmic-ray charged particles over a wide energy. Thanks to a couple of layers of segmented plastic scintillators placed on top of the detector, the instrument is able to identify the charge of individual elements from proton to iron (and above). The imaging tungsten scintillating fiber calorimeter provides accurate particle tracking and the lead tungstate homogeneous calorimeter can measured the energy with a wide dynamic range. One of the CALET scientific objectives is to measure the energy spectra of cosmic rays to shed light on their acceleration and propagation in the Galaxy. By the observation in first five years, a precise measurement of the iron spectrum is now available in the range of kinetic energy per nucleon from 10 GeV/n to 2 TeV/n. The CALET’s result with a description of the analysis and details on systematic uncertainties will be illustrated. Also, a comparison with previous experiments’ results is given

CALET on the International Space Station: new direct measurements of cosmic-ray iron and nickel

The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, collected a large sample of cosmic-ray over a wide energy interval. Approximately 20 million triggered events per month are recorded with energies > 10 GeV. The instrument identifies the charge of individual elements up to nickel and beyond and, thanks to a homogeneous lead-tungstate calorimeter, it measures the energy of cosmic-ray nuclei providing a direct measurement of their spectra. Iron and nickel spectra are a low background measurement with negligible contamination from spallation of higher mass elements. Iron and nickel nuclei play a key role in understanding the acceleration and propagation mechanisms of charged particles in our Galaxy. In this contribution a direct measurement of iron and nickel spectra, based on more than five years of data, are presented in the energy range from 10 GeV/n to 2 TeV/n and from 8.8 GeV/n to 240 GeV/n, respectively. The spectra are compatible within the errors with a single power law in the energy region from 50 GeV/n to 2 TeV/n and from 20 GeV/n to 240 GeV/n, respectively. Systematic uncertainties are detailed and the nickel to iron flux ratio is presented. This unprecedented measurement confirms that both elements have very similar fluxes in shape and energy dependence, suggesting that their origin, acceleration, and propagation might be explained invoking an identical mechanism in the energy range explored so far

Editorial: Biomimetic and bioinspired membranes to reconstruct the properties of natural systems

Editorial on the Research TopicPeer reviewe

An Advanced Technological Lightweighted Solution for a Body in White

Funded by the EC FP7 Program, EVolution project is using the Pininfarina Nido concept car as a baseline for its activities, with the goal to demonstrate the sustainable production of a full electric 600 kg vehicle (FEV). The project has to be finalized by the end of 2016. The existing Body in White (BiW) has been completely reviewed through a design strategy aiming to reduce the number of parts and using innovative lightweight materials and technologies. The considered Al technologies applied on high performances Al alloys provide the opportunities to obtain components with complex geometries and low thickness, merging different parts into one unique element. Besides, it is possible to process a variable thickness element with a single operation. A “green sand mold” technique allows co-casted joints among elements produced with different Al manufacturing processes. The potential cost reduction and process simplification in terms of time and assembly are promising: current state-of-the-art, based on traditional moulds, does not allow these opportunities. The BiW has been hybridized in certain areas of the underbody with a composite material of the PA family, reinforced with GF. This material has been obtained improving existing ones and developing a production process suitable for scaling to commercial requirements, throughout an advanced sheet thermoforming and 3D-injection method (CaproCAST process). Novel polypropylene nanocomposites (PNC) based on silicate and glass fiber layers demonstrate improved toughness and stiffness and have been selected for crash cross beam and side door. Polyurethane foams based on recycled polymers are explored as sustainable energy-absorbing filling in cross beam sections. Structural epoxy adhesives have been considered to join the BiW parts and welding points are reduced in number: in certain areas spot-welds have been used only to tack the parts during polymerization. In addition to the previous results, current weight of the BiW is 115 kg versus 160 kg of the baseline car. An FE-analysis on the virtual full vehicle indicates a good structural behavior, considering EU standards of crash homologation and global static and dynamic performances. The developed architecture and the integration of lightweight materials will ensure that the EU maintains its competitiveness against the Asian and United States automobile industries. This topic is focused on the results obtained on the BiW in terms of design strategies, Al and composite materials innovative technologies and joining methods.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 314744

CALET measurements with cosmic nuclei: expected performances of tracking and charge identification

CALET is a space mission currently in the final phase of preparation for a launch to the International Space Station (ISS), where it will be installed on the Exposed Facility of the Japanese Experiment Module (JEM-EF). In addition to high precision measurements of the electron spectrum, CALET will also perform long exposure observations of cosmic nuclei from proton to iron and will detect trans-iron elements with a dynamic range up to Z = 40. The energy measurement relies on two calorimeter systems: a fine grained imaging calorimeter (IMC) followed by a total absorption calorimeter (TASC) for a total thickness of 30 X0 and 1.3 proton interaction length. A dedicated module (a charge detector, CHD), placed at the top of the apparatus, identifies the atomic number Z of the incoming cosmic ray. In this paper, the IMC performances in providing tracking capabilities and a redundant charge measurement by multiple dE dx samples are studied for the case of proton and He identification with a preliminary version of the analysis. The CALET mission is funded by the Japanese Space Agency (JAXA), the Italian Space Agency (ASI), and NASA

The co-existence of transcriptional activator and transcriptional repressor MEF2 complexes influences tumor aggressiveness

The contribution of MEF2 TFs to the tumorigenic process is still mysterious. Here we clarify that MEF2 can support both pro-oncogenic or tumor suppressive activities depending on the interaction with co-activators or co-repressors partners. Through these interactions MEF2 supervise histone modifications associated with gene activation/repression, such as H3K4 methylation and H3K27 acetylation. Critical switches for the generation of a MEF2 repressive environment are class IIa HDACs. In leiomyosarcomas (LMS), this two-faced trait of MEF2 is relevant for tumor aggressiveness. Class IIa HDACs are overexpressed in 22% of LMS, where high levels of MEF2, HDAC4 and HDAC9 inversely correlate with overall survival. The knock out of HDAC9 suppresses the transformed phenotype of LMS cells, by restoring the transcriptional proficiency of some MEF2-target loci. HDAC9 coordinates also the demethylation of H3K4me3 at the promoters of MEF2-target genes. Moreover, we show that class IIa HDACs do not bind all the regulative elements bound by MEF2. Hence, in a cell MEF2-target genes actively transcribed and strongly repressed can coexist. However, these repressed MEF2-targets are poised in terms of chromatin signature. Overall our results candidate class IIa HDACs and HDAC9 in particular, as druggable targets for a therapeutic intervention in LMS