726 research outputs found
The P¯ANDA Experiment at FAIR
Abstract At Darmstadt, in Germany, is under construction FAIR a new international Facility for Antiproton and Ion Research. This will provide scientists in the world with outstanding beams and experimental conditions for studying matter at the level of atoms, nuclei, and other sub-nuclear constituents. An antiproton beam with intensity up to 2 × 10 7 p ¯ / s and high momentum resolution will be available at the High Energy Storage Ring (HESR) where the P ¯ ANDA detector will be installed. P ¯ ANDA will carry out a wide scientific program including meson spectroscopy from light to charm quark sector, baryon/antibaryon production, charm in nuclei, and strangeness physics with particular attention to the systems with strangeness S = − 2 . In this paper will be illustrated the details of the P ¯ ANDA scientific program related to strangeness physics, after a brief introduction about the FAIR facility
Report: Fundamental Physics at Frascati
This report summarizes the scientific discussion of the workshop "Fisica Fondamentale a Frascati" that was held on January the 13th, 2021. The aim of the meeting was to brainstorm on the opportunities to continue to carry out at the LNF experimental activities that could contribute to the scientific exploration of fundamental open questions in particle physics. This initiative has been triggered by the awareness that while the ongoing DA NE scientific program is coming to an end, the EuPRAXIA project, identified as the major future activity of the LNF, has a time horizon of several years before entering the operation phase. Therefore, we asked ourselves to which fields in fundamental physics the LNF can give a sound contribution within the medium-term by exploiting the existing infrastructures or, in case some breakthrough for some specific research is foreseeable, by implementing minor upgrades. The topics that have been identified are: (i) the quest for dark matter candidates in terms of feebly interacting light particles; (ii) probing the axion solution to the strong CP puzzle by searching for dark matter axions with superconducting cavities and with large volume haloscopes; (iii) the study of the low energy QCD problems related to the role of strangeness in nuclear matter. Theoreticians and experimentalists convened to scrutinize the different aspects of these scientific issues. The format chosen for the workshop foresaw a theory talk introducing each subject, followed by experimental contributions describing in detail how the scientific goal can be best addressed. This document resumes the various contributions in a condensed form, and is intended to provide a guideline for who will be asked to evaluate this program. Additional material can be found at the webpage of the meeting (https://agenda.infn.it/event/25299/)
The investigation on the dark sector at the PADME experiment.
Abstract The PADME experiment, at the Laboratori Nazionali di Frascati (LNF) of INFN, is designed to be sensitive to the production of a low mass gauge boson A ′ of a new U ( 1 ) symmetry holding for dark particles. The DA Φ NE Beam-Test Facility of LNF is providing a high intensity, mono-energetic positron beam impacting on a low Z target to provide e + e − annihilations, where the dark photon can be produced along with an ordinary photon. Simulation studies predict a sensitivity on the interaction strength ( e 2 parameter) down to 10−6, in the mass region 1 MeV/ c 2 M A ′ 23.7 MeV/ c 2 , for one year of data taking with a 550 MeV beam. In 2018 the first run will take place, and early data will give the opportunity to compare the detector performance with the design parameters. Right now, an intense activity is taking place to install and commission the PADME experimental apparatus on site
Exotic atoms at extremely high magnetic fields: the case of neutron star atmosphere
The presence of exotic states of matter in neutron stars (NSs) is currently
an open issue in physics. The appearance of muons, kaons, hyperons, and other
exotic particles in the inner regions of the NS, favored by energetic
considerations, is considered to be an effective mechanism to soften the
equation of state (EoS). In the so-called two-families scenario, the softening
of the EoS allows for NSs characterized by very small radii, which become
unstable and convert into a quark stars (QSs). In the process of conversion of
a NS into a QS material can be ablated by neutrinos from the surface of the
star. Not only neutron-rich nuclei, but also more exotic material, such as
hypernuclei or deconfined quarks, could be ejected into the atmosphere. In the
NS atmosphere, atoms like H, He, and C should exist, and attempts to model the
NS thermal emission taking into account their presence, with spectra modified
by the extreme magnetic fields, have been done. However, exotic atoms, like
muonic hydrogen or the so-called Sigmium , could
also be present during the conversion process or in its immediate aftermath. At
present, analytical expressions of the wave functions and eigenvalues for these
atoms have been calculated only for H. In this work, we extend the existing
solutions and parametrizations to the exotic atoms and
, making some predictions on possible transitions. Their
detection in the spectra of NS would provide experimental evidence for the
existence of hyperons in the interior of these stars.Comment: 10 pages, 6 figures, proceedings of the "International Conference on
Exotic Atoms and Related Topics - EXA2017", Austrian Academy of Sciences,
Austria, September 11-15, 201
Measurement of Thermal Conductivity and Thermal Diffusivity of Porcine and Bovine Kidney Tissues at Supraphysiological Temperatures up to 93 °C
This experimental study aimed to characterize the thermal properties of ex vivo porcine and bovine kidney tissues in steady-state heat transfer conditions in a wider thermal interval (23.2-92.8 & DEG;C) compared to previous investigations limited to 45 & DEG;C. Thermal properties, namely thermal conductivity (k) and thermal diffusivity (& alpha;), were measured in a temperature-controlled environment using a dual-needle probe connected to a commercial thermal property analyzer, using the transient hot-wire technique. The estimation of measurement uncertainty was performed along with the assessment of regression models describing the trend of measured quantities as a function of temperature to be used in simulations involving heat transfer in kidney tissue. A direct comparison of the thermal properties of the same tissue from two different species, i.e., porcine and bovine kidney tissues, with the same experimental transient hot-wire technique, was conducted to provide indications on the possible inter-species variabilities of k and & alpha; at different selected temperatures. Exponential fitting curves were selected to interpolate the measured values for both porcine and bovine kidney tissues, for both k and & alpha;. The results show that the k and & alpha; values of the tissues remained rather constant from room temperature up to the onset of water evaporation, and a more marked increase was observed afterward. Indeed, at the highest investigated temperatures, i.e., 90.0-92.8 & DEG;C, the average k values were subject to 1.2- and 1.3-fold increases, compared to their nominal values at room temperature, in porcine and bovine kidney tissue, respectively. Moreover, at 90.0-92.8 & DEG;C, 1.4- and 1.2-fold increases in the average values of & alpha;, compared to baseline values, were observed for porcine and bovine kidney tissue, respectively. No statistically significant differences were found between the thermal properties of porcine and bovine kidney tissues at the same selected tissue temperatures despite their anatomical and structural differences. The provided quantitative values and best-fit regression models can be used to enhance the accuracy of the prediction capability of numerical models of thermal therapies. Furthermore, this study may provide insights into the refinement of protocols for the realization of tissue-mimicking phantoms and the choice of tissue models for bioheat transfer studies in experimental laboratories
Beam test of ALPIDE Sensor
The Alice Pixel Detector (ALPIDE) is developed for the upgrade of the Inner Tracking System of the ALICE experiment at CERN, which will take place during second Long Shutdown in 2019-2020. ALPIDE is a Monolithic Active Pixel Sensor (MAPS), manufactured in a 180 nm CMOS Imaging Process of TowerJazz. Forecoming tracking detectors, based on this technology, will see strong advantages with the application of these sensors as they provide the highest capabilities in spatial resolution and utmost potential for being thin. In this work, the results of the ALPIDE sensor beam test, which took place at the Beam Test Facility of Laboratori Nazionali di Frascati, are presented
The On-Site Analysis of the Cherenkov Telescope Array
The Cherenkov Telescope Array (CTA) observatory will be one of the largest
ground-based very high-energy gamma-ray observatories. The On-Site Analysis
will be the first CTA scientific analysis of data acquired from the array of
telescopes, in both northern and southern sites. The On-Site Analysis will have
two pipelines: the Level-A pipeline (also known as Real-Time Analysis, RTA) and
the level-B one. The RTA performs data quality monitoring and must be able to
issue automated alerts on variable and transient astrophysical sources within
30 seconds from the last acquired Cherenkov event that contributes to the
alert, with a sensitivity not worse than the one achieved by the final pipeline
by more than a factor of 3. The Level-B Analysis has a better sensitivity (not
be worse than the final one by a factor of 2) and the results should be
available within 10 hours from the acquisition of the data: for this reason
this analysis could be performed at the end of an observation or next morning.
The latency (in particular for the RTA) and the sensitivity requirements are
challenging because of the large data rate, a few GByte/s. The remote
connection to the CTA candidate site with a rather limited network bandwidth
makes the issue of the exported data size extremely critical and prevents any
kind of processing in real-time of the data outside the site of the telescopes.
For these reasons the analysis will be performed on-site with infrastructures
co-located with the telescopes, with limited electrical power availability and
with a reduced possibility of human intervention. This means, for example, that
the on-site hardware infrastructure should have low-power consumption. A
substantial effort towards the optimization of high-throughput computing
service is envisioned to provide hardware and software solutions with
high-throughput, low-power consumption at a low-cost.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
Expected performance of the ASTRI-SST-2M telescope prototype
ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is an
Italian flagship project pursued by INAF (Istituto Nazionale di Astrofisica)
strictly linked to the development of the Cherenkov Telescope Array, CTA.
Primary goal of the ASTRI program is the design and production of an end-to-end
prototype of a Small Size Telescope for the CTA sub-array devoted to the
highest gamma-ray energy region. The prototype, named ASTRI SST-2M, will be
tested on field in Italy during 2014. This telescope will be the first
Cherenkov telescope adopting the double reflection layout in a
Schwarzschild-Couder configuration with a tessellated primary mirror and a
monolithic secondary mirror. The collected light will be focused on a compact
and light-weight camera based on silicon photo-multipliers covering a 9.6 deg
full field of view. Detailed Monte Carlo simulations have been performed to
estimate the performance of the planned telescope. The results regarding its
energy threshold, sensitivity and angular resolution are shown and discussed.Comment: In Proceedings of the 33rd International Cosmic Ray Conference
(ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at arXiv:1307.223
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